3X+5X = 48 14X-8X = 12 6 * 5+2X = 44

20X-50 = 50 28+6X = 88 32-22X = 10

24-3X = 3 10X *(5+ 1)= 60 99X = 100-X

X+3 = 18 X-6 = 12 56-2X = 20

4y+2=6 x+32=76 3x+6= 18

16+8x=40 2x-8=8 4x-3*9=29

8x-3x= 105 x-6*5=42 x+5=7

2x+3 = 10 12x-9x = 9 6x+ 18 = 48

56x-50x=30 5x= 15 78-5x=28

32y-29=3 5x+5= 15 89x-9=80

100-20x = 20 55x-25x = 60 76y-75 = 1

23y-23 = 23 4x-20 = 0 80y+20 = 100

53x-90 = 16 2x+9x = 1 1 12y- 12 = 24

80+5x = 100 7x-8 = 6 65x+35 = 100

3X-2/3 = 1/3 5/6+X = 7/8 X-2/5 = 3/7 6X+4/9 = 4/9

3x- 14×2 = 1 1 1/7+ 1/2x = 2/3

(6+4)X = 100 X+7 1/29X = 5. 1x-8 =(40-X)+4(X+2+ 1)/(X- 1)= 2

(x+3)/9- 1/8 = x/8 5x = 180 120 x/2+48 = 239 120 x+28 = 280 130+52x = 270

1502- 1320 = 3x+ 18 3x+2 = 2x 7

exclusive of

1)50+ 160÷40 (2) 120- 144÷ 18+35 (3)347+45×2-4 160÷52

(4)(58+37)÷(64-9×5) (5)95÷(64-45) (6) 178- 145÷5×6+42

(7)8 12-700÷(9+3 1× 1 1) ( 8)85+ 14×( 14+208÷26)

(9)(284+ 16)×(5 12-8208÷ 18) ( 10) 120-36×4÷ 18+35

( 1 1)(58+37)÷(64-9×5) ( 12)(6.8-6.8×0.55)÷8.5

( 13)0. 12× 4.8÷0. 12×4.8 ( 14)(3.2× 1.5+2.5)÷ 1.6

( 15)3.2×( 1.5+2.5)÷ 1.6 ( 16)6- 1.6÷4 ( 17)7.2÷0.8- 1.2×5

( 18)6.5×(4.8- 1.2×4) ( 19)0.68× 1.9+0.32× 1.9

(20) 10. 15- 10.75×0.4-5.7 (2 1)5.8×(3.87-0. 13)+4.2×3.74

(22)32.52-(6+9.728÷3.2)×2.(23)( 136+64)×(65-345÷23)

(24) 420+580-64×2 1÷28 (25)(58+370)÷(64-45)

Second, use the ladder equation to calculate.

⑴6.9+4.8+3. 1 ⑵ 0.456+6.22+3.78 ⑶ 15.89+(6.75-5.8)×6

⑷4.02+5.4+0.98 ⑸5. 17- 1.8-3.2 ⑹ 13.75-(3.75+6.48)×6

⑺3.68+7.56-2.68 ⑻7.85+2.34-0.85+4.66 ⑼35.6- 1.8- 15.6-7.2

⑽3.82+2.9+0. 18+9. 1 ⑾9.6+4.8-3.6 ⑿ 7. 14-0.53-2.47

⒀5.27+2.86-0.66+ 1.63 ⒁ 13.35-4.68+2.65 ⒂73.8- 1.64- 13.8-5.36

application problem

1. How many square meters of iron sheets does it take to make a rectangular chimney with a cross section of a square with a side length of 4 cm and a height of 2 m?

The iron sheet of each chimney

0.4× 4× 2 = 3.2 square meters

At least 30 such chimneys are made of iron sheets.

3.2× 30 = 96 square meters

2. A rectangular wooden box, length1.2m, width 0.8m and height 0.6m.. How many square meters of planks does it take to make this wooden box?

(1.2× 0.8+1.2× 0.6+0.8× 0.6) × 2 = 4.32 square meters.

What if this wooden box is not covered properly?

1.2× 0.8+(1.2× 0.6+0.8× 0.6 )× 2 = 3.36 square meters.

3. A cuboid (including a cube) consists of eight cubes with a side length of 1cm, of which the smallest surface area is?

The smallest surface area is a cube with a length of 2 cm.

What is the minimum surface area?

2× 2× 6 = 24 cm2

The processing factory will process a batch of washing machine jackets (bottomless). Each laundry machine is 60 cm long, 40 cm wide and 80 cm high. How many square meters of cloth does it take to make 1250 sets?

60x40+2x(40x80+60x80)

=2400+2x(3200+4800)

=2400+ 16000

= 18400 (square centimeter) = 1.84 (square meter)

1.84x 1250=2300 (m2)

The surface area of a cuboid is 96 square meters, and the two opposite sides are squares. The side length of a square is 2 decimetres. What is the height of this cuboid?

What is the bottom area of a cuboid?

2× 2 = 4 (square decimeter)

The areas of the front, back, left and right sides of a cuboid are

96-4× 2 = 88 (square decimeter)

The circumference of the bottom of the cuboid is

2× 4 = 8 (decimeter)

What is the height of a cuboid?

88 ÷ 8 = 1 1 (decimeter)

1. The capacity of a rectangular water tank is 320 liters. The bottom of this water tank is a square with a side length of 8 decimeters. What is the height of the water tank?

The classroom of Class 2.2 (1) is on the second floor (* * * fourth floor). The classroom is 10 meter long, 6 meters wide and 4 meters high, and the door and window area is 19.6 square meters. If the interior wall is painted with 0.25 kilograms of paint per square meter, how many kilograms of paint does * * need?

3. A rectangular iron sheet with a length of 26 cm and a width of 16 cm was cut from the four corners and welded into an open iron box. What is the volume of this iron box?

4. In a rectangular container with a length of 20 decimeters and a width of 15 decimeters, there is water with a depth of 20 decimeters. Now a 30-decimeter-long cubic iron block sinks into the water. What is the water depth in the container at this time?

5. Saw a cuboid block 6 cm long, 5 cm wide and 4 cm high into two small cuboids. How many square centimeters can the surface area be increased at most?

6. A 2-meter-long rectangular steel was cut into three sections, and its surface area increased by 2.4 square decimeters. What is the original volume of this steel?

7. If the height of a cuboid is reduced by 3 cm, it becomes a cube. At this time, the surface area decreased by 96 square centimeters. How many cubic centimeters was the original cuboid?

8. The tap water pipe on the outer wall of the building is a cuboid. If each segment is 15 decimeter long, then the cross section is a rectangle with a length of 1 decimeter and a width of 0.6 decimeter. How many square decimeters does it take to make a water-saving pipe?

1, rectangular box, length 24 cm, width 12 cm, height 9 cm. How many square centimeters is its surface area?

2. The side length of the cube is10cm. What is its surface area?

3. How many square meters of wood does Qiang Qiang need to make a simple wardrobe with a length of 0.75m, a width of 0.5m and a height of1.6m?

4. A cube gift box with a length of 1.2 decimeter. How many square decimetres of wrapping paper does it take to wrap this gift box?

5. There is an iron mailbox in Honglou Square, which is 50 cm long, 40 cm wide and 78 cm high. How many square centimeters of iron does it take to make this mailbox?

6. A rectangular biscuit box, length10cm, width 6cm and height12cm. What is the minimum area of this trademark paper if it is labeled all around (not the upper and lower sides)?

7. The processing factory should process a batch of washing machine jackets (bottomless). Each laundry machine is 60 cm long, 40 cm wide and 80 cm high. How many square meters of cloth does it take to make 1250 sets?

8. A university has an abandoned swimming pool, which is 5 meters long, twice as wide and 3 meters deep. Its periphery and bottom are covered with tiles. How many square meters of tiles has this university wasted?

9. We must paint the classroom in Class One, Grade Five. It is known that the classroom is 8 meters long, 6 meters wide and 3 meters high, and the door and window area 12 square meter should be deducted. If 5 yuan is required for painting per square meter, how much will it cost to paint our classroom?

10. A fish pond is 28m long,15m wide and 2m deep. How many square meters does it cover? How many cubic meters of water can you store at most?

1 1. The rectangle is 7 meters long, 6 meters wide and 4 meters high. How many cubic meters is its volume?

12, a cubic stone with a side length of 8 meters, what is its volume in cubic meters?

13, a cuboid wood, 5 meters long, with a cross-sectional area of 0.06 square meters. What is the volume of this piece of wood?

14. The construction site is 50 meters long, 30 meters wide and 50 centimeters deep. How many cubic holes should be dug?

15. What is the volume of an ice cube 60 cm long?

16, Teacher Yang wants to give you (69 people) a birthday cake with a length of 3 cm, a width of 2 cm and a height of 0.5 cm. How many cubic centimeters does each student get (haha, is it too small? )

17. The furniture factory wants to order 1000 square timber, each with a cross-sectional area of 24 decimeters and a length of 3 meters. How many squares are there in these squares?

18. The school will build a fence with a length of 15m, a thickness of 24cm and a height of 3m. If 525 bricks are used per cubic meter, how many bricks are used in this wall?

19, the side lengths of cuboids and cubes, etc. Suppose that the rectangular body is 6 decimeters long, 5 decimeters wide and 4 decimeters high, what is the side length of this cube? Are they equal in volume? If not, how many cubic decimeters are they?

20. A rectangular glass container, measure the length and width of 2 centimeters from the inside, pour 5.5 liters of water into the container, and then put an apple in the water. At this time, the measured water depth in the container is 15 cm. How big is this apple?

2 1. The ice used in Harbin Ice and Snow World can melt about 80,000 cubic meters of water every year. How many swimming pools are 50 meters long, 25 meters wide and 1.2 meters deep?

22. A train car, measured from the inside, is 13m long, 2.5m wide, with a coal height of 1.5m and a coal weight of 1.33t per cubic meter. How many tons of coal does this car have? Please calculate carefully. )

23. In order to solve the problem of freshwater shortage, a freshwater reservoir was built on an island, with a length of 22 meters, a width of 10 meter and a depth of 1.8 meter. How many square meters is this reservoir? How many cubic meters of water can be stored?

24. The sum of the sides of a cuboid is 72 meters, 6 meters long, 4 meters wide and how many meters high? How many square meters is the surface area? How many cubic meters is the volume?

Is the landlord satisfied? I'll take another look.