2=85;

6)c=22.5

7)acb=85

You can't type the symbol of the p.s. angle.

The answer to the seventh question on page 135 of the second volume of the first day of the People's Education Edition: Suppose the annual profit of the whole factory was X million yuan the year before last.

According to the meaning of the question, (x+10)/(280-40)-x/280 ≥ 0.6, so x≥308.

A: The annual profit of the whole factory in the previous year was at least 3.08 million yuan.

The answers to the second and third questions in the second volume of the first-grade math book 8.2 are1.3u+2t = 716u-2t =11②.

①+②=3u+2t+6u-2t=9u= 18

D: u=2

Bring u=2 into ① and get: t= half.

The solution of the equations is: u=2 t= half.

2.2a+b=3① 3a+b=4②

①-②=2a+b-3a-b=-a=- 1

De: a= 1

Bring a= 1 into ① to get b= 1.

The solution of the equations is: a= 1 b= 1.

3.2x-5y=-3① -4x+y=-3②

②×5=-20x+5y=- 15 ③

①+③= 2x-5y-20x+5y =- 18x =- 18

De: x= 1

Bring x= 1 into ① and get: y= 1.

The solution of the equations is: x= 1 y= 1.

4. 1/2x-3/2y =- 1①2x+y = 3②

①×4=2x-6y=-4 ③

②-③=2x+y-2x+6y=7y=7

De: y= 1

Bring y= 1 into ① and get: x= 1.

The solution of the equations is: y= 1 x= 1.

It's online. Do you think this is it?

The answers and process of questions 6 and 7 on page 9 1 of the second volume of the first day of the People's Education Edition (6) Solution: Let the number of times of ∠A be x, then ∠ 1 is (x+ 10).

According to the meaning: x+(x+ 10)+42 = 180.

2x+52 = 180

2x= 128

x=64

∫∠A is 64 (proven) and∠∠ ∠ACD is 64 (known).

∴∠A=∠ACD

∴ABCD (internal dislocation angles are equal and two straight lines are parallel)

(7) solution: let the degree of ∠C be x.

According to the meaning of the question: x+x+0.5x = 180.

2.5x= 180

x=72

∫BD is the height of the AC side.

∴∠BDC=90

∫∠DCB = 72 (certification)

∴∠ DBC =180-∠ BDC-∠ DCB =180-90-72 =18 (interior angle and theorem of triangle)

The answer to the eighth question on page 135 of the second volume of the first day of the People's Education Edition is that the merchant sets the price at least as X, that is, he loses 1.5 when he buys a catty of apples, and at least 1.5 yuan after the sale.

( 1-5%)x & gt； = 1.5

x & gt=30/ 19

X & gt= 1.58

The answer to the ninth question on page 142 of the second volume of the first mathematics book of the People's Education Press: Suppose there are X people and there are (3x+8) books.

We can get 3x+8-5 (x-1) < 3 3x+8-5 (x-1) > = 0 from the equations.

Solution: 5

A: Six people, 26 books.

That's the question: how many students should I share some with? .........................

This question was said by the teacher, please feel free to adopt it. . . . . . . . . . . . . . . .

The answer to the ninth question on page 104 of the second volume of the first day of the People's Education Edition: Let the length of the rectangle be x cm and the width be y cm.

According to the meaning of the question

X-5=y+2

Xy=(X-5)(y+2)

Through this set of equations, we can get

X=25/3

y=4/3

A: The length of a rectangle is 25/3 cm and the width is 4/3 cm.

Centimeter.

People's Education Press, Volume 2, Grade 1 103, the answer and process of the fifth question 3x+4y= 16 ①.

5x-6y=33 ②

( 1) x 5:

15x+20y=80 ③

②×3:

15x- 18y=99 ④

③-④ Obtain:

38y=- 19

y=-？

Will y=-? Substitute into ① to get:

3x-2= 16

3x= 18

x=6

So:

x=6

y=-？

(People's Education Edition) The answers to the questions 1 1, 12, 13 on page 100 of the second volume of the junior high school mathematics book are all big brothers or big sisters, but there is no such question on page 100! Only example 3 and induction and thinking wow. . . . . .

I suggest you put on a pair of eyes. . . . .

Match just lent ... don't post the question, otherwise you have already done it.