The answer to the second volume of the seventh grade mathematics basic training (1) 1, =-0.5 =2.
2. Omission
3. Omission
4、- 1.50062? 10^4
5、-0.00203
6 、- 1/( 1+2a)-3/(2ab 2(x-y)
7 、& lt-2.5 & lt； & gt
8, expand 5 times
Multiple choice ABC
12 、( 1)= b/(a+b)(2)= 3/(x- 1)(3)=(x-y)2/xy？ xy/(x+y)2 =(x ^ 2-2xy+y ^ 2)/(x ^ 2+2xy+y ^ 2)(4)=(32x^7)/(9 y^3)
13、x- 12=2x+ 1 x= 1
14, (1) x into the original formula = (-2/5? 2k)/-6/5k = 8/5 k=-5
(2) Original formula = x 2/(x 2+x) When x=- 1/2, the original formula =- 1.
15, the reciprocal of the original formula = 3 (x 2+1/x 2-1) =-9/4.
16, original formula =(a+ab+abc)? (a+ab+abc)= 1
17, let Xiao Li x, Xiao Wang x+2. 60/(x+2)=48/x x=8 x+2= 10
1, (1) right 4 down 5 down 5 right 4 o'clock a? Point b, point c B line? c？
(2) the same distance
(3) Equality, equality, equality
(4) Shape
(5) Distance
(6) Omission
2. Draw this picture yourself.
(1) fixed point This fixed point
(2) The centers of rotation are equal, equal and equal.
(3) Size and shape
(4) Omission
Step 3 draw by yourself
( 1) 180? Another figure, two figures, this point, two figures form a central symmetry, symmetrical central intersection.
(2) The rotation angle of the initial rotation center is 0? & lt？ & lt360? & lt& gt
(3) 180? Symmetric center of initial graph
(4) Omission
Step 4 draw by yourself
(1) is an axisymmetric straight line.
(2) Equality, equality, sameness and invariability
(3) perpendicular to the midpoint of two pairs of corresponding points
(4) Axisymmetric graphic straight lines that coincide with each other.
(5) The median perpendicular to the midpoint of countless sides of a straight line passing through the center of the circle.
(6) Omission
5、C 90？ Point a, point e, line CA, line CE? The isosceles right angle at the midpoint q of alternating current
1, draw all by yourself.
2. Sketch (2) Rotate clockwise 1 19? Or rotate 24 1 counterclockwise?
3.Sketch (1) translates AB and a? b？ , AC and a? c？ , BC and B? c？
(2) Rotate 90 counterclockwise? 90 90
(3) Rotate counterclockwise (clockwise) around point O 180? (Point O is marked separately on the drawing)
The seventh grade mathematics basic training Volume II answer (2) 1, translation, rotation and folding.
2. Location, shape and size
3、 90?
4, the center of the circle
5、 8
6.yes, yes
7, high temperature oxidation
8. Translate, rotate and fold dimensions and shapes.
9、C
10、D
1 1、C
12, sketch
13, sketch
14, sketch
15, sketch
16, sketch
17, point c, point b, midpoint of BC line.
18, let EC be x cm. 8∶5=x∶4 x=6.04
1、2a^7 (y 2x 2)/x 2y 2
2、3/2m 2x -2/(x+3)
3、xy(y-x)(x+ 1)(x- 1)(x+3)(x-3)
4 、(-3y 3)/x 2z
5、6
6, equilateral triangle
7、 169/4 ?
Multiple choice question CB
The seventh grade mathematics basic training Volume II Answer: Chapter VI, One Yuan Linear Equation? 6. 1 From practical problems to equations
I. 1. D 2。 A 3。 A
2. 1 . x =-6 2.2x- 15 = 25 3 . x = 3( 12-x)
3. 1. Solution: If the production and operation water consumption is x billion cubic meters, the household water consumption is (5.8-x) billion cubic meters, and the equation can be listed as follows:
5.8-x=3x+0.6
2. Solution: If an apple buys X kilograms, the equation can be listed as: 4x+3(5-x)= 17.
3. Solution: Let the number of the original extracurricular math group be X, then the equation can be listed as:
? 6.2 Solve the linear equation of one variable (1)
I. 1. D 2。 C 3。 A
2. 1.x=-3, x= 2. 10 3. x=5。
Three. 1 . x = 72 . x = 43 . x = 4 . x = 5 . x = 36 . y =
? 6.2 Solving the linear equation of one variable (2)
I. 1. B 2。 D 3。 A
Two. 1.x=-5，y = 3 ^ 2。 3.-3
Three. 1.( 1)x =(2)x =-2(3)x =(4)x =-4(5)x =(6)x =-2。
2.( 1) Suppose the table tennis team in Class Two, Grade One * * has X people, and get: 9x-5=8x+2. Get: X = 7 (2) There are 48 people.
3.( 1)x=-7 (2)x=-3
? 6.2 Solving the linear equation of one variable (3)
I./kloc-0 1.C2.D3.B4.B
Second, 1. 1 2.3. 10
Three. 1.( 1) x = 3 (2) x = 7 (3) x =？ 1 (4)x= (5) x=4 (6) x=
2.3( x-2) -4(x- )=4 and x =-3 3. 3 yuan.
? 6.2 Solving the linear equation of one variable (4)
I. 1. B 2。 B 3。 D
Two. 1.5 2., 3.4. 15
Three. 1.( 1) y = (2) y = 6 (3) (4) x =
2. Solve Equation 3(5x-6)=3-20x to get x=, and substitute x= into Equation a- x=2a+ 10x to get a =-8.
? When a=-8, Equation 3(5x-6)=3-20x has the same solution as Equation a- x=2a+ 10x.
3. Solution: x=9
? 6.2 Solve the linear equation of one variable (5)
I. 1. A 2。 B 3。 C
2. 1.2(x+8)= 40 ^ 2。 4,6,8 3.2x+1 0 = 6x+54.155.160 yuan 3,1. Suppose x people transfer to a, according to the meaning of the question.
2. Suppose the user's water consumption in May is X tons, which means 1.2 according to the question? 6+2(x-6)= 1.4 x。