1) 3(2,5 – 2x) = 13,5 – 14x 2) 0,6y – 1,5 = 0,3(y – 4) 3) 0,5(4 – 2a) = a – 1,8 4) 7(3 +...

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1) 3(2,5 – 2x) = 13,5 – 14x 2) 0,6y – 1,5 = 0,3(y – 4) 3) 0,5(4 – 2a) = a – 1,8 4) 7(3 + x) = 2(x – 5) + 8 5) –0,2(5 – 0,7x) + 0,02 = 1,4(x–1,6) 6) 1,2(3b + 5) = 2(2,4b – 3,6) 7) 3,2(5x – 1) = 3,6x – 9,4 8) 8(0,7x – 4) – 2(0,2x – 3) = – 39 9) –3(2,1z – 4)– 4,2 = 1,2(– 5z+ 0,5) 10) 6,4(2 – 3y) = 6(0,8y – 1) + 6,8


Математика (16 баллов) | 61 просмотров
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Пошаговое объяснение:

3(2,5 – 2x) = 13,5 – 14x

7.5 - 6*x = 13.5 - 14x

-6*x + 14*x = 13.5 - 7.5

8*x= 6

x= 0.75

2) 0,6y – 1,5 = 0,3(y – 4)

0.6y - 0.3y = -1.2+1.5

0.3y = 0.3

y= 1

3) 0,5(4 – 2a) = a – 1,8

2-10a = a-1.8

-1a - 1a=-2-1.8

-2a= -3.8

a= 1.9

4) 7(3 + x) = 2(x – 5) + 8

21+7x = 2x- 10 + 8

7x - 2x = -10 + 8 -21

5x= -23

x= -4.6

5) –0,2(5 – 0,7x) + 0,02 = 1,4(x–1,6)

-1+0.14x +0.02 = 1.4x -2.24

0.14x-1.4x = -2.24 -0.02 +1

-1.26х = -1.26

x= 1

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1) 3(2,5 – 2x) = 13,5 – 14x

7.5-6x=13.5-14x

-6x+14x=13.5-7.5

8x=6

x=6/8

x=0.75

2) 0,6y – 1,5 = 0,3(y – 4)

0.6y-1.5=0.3y-1.2

0.6y-0.3y=-1.2+1.5

0.3y=0.3

y=0.3/0.3

y=1

3) 0,5(4 – 2a) = a – 1,8

2-a=a-1.8

-a-a=-1.8-2

-2a=-3.8

a=-3.8/(-2)

a=1.9

4) 7(3 + x) = 2(x – 5) + 8

21+7x=2x-10+8

7x-2x=-2-21

5x=-23

x=-23/5

x=-4.6

5) –0,2(5 – 0,7x) + 0,02 = 1,4(x–1,6)

-1+0.14x+0.02=1.4x-2.24

0.14x-1.4x=-2.24+1-0.02

-1.26x=-1.26

x=-1.26/(-1.26)

x=1

6) 1,2(3b + 5) = 2(2,4b – 3,6)

3.6b+6=4.8b-7.2

3.6b-4.8b=-7.2-6

-1.2b=-13.2

b=-13.2/(-1.2)

b=11

7) 3,2(5x – 1) = 3,6x – 9,4

16x-3.2=3.6x-9.4

16x-3.6x=-9.4+3.2

12.4x=-6.2

x=-6.2/12.4

x=-0.5

8) 8(0,7x – 4) – 2(0,2x – 3) = – 39

5.6x-32-0.4x+6=-39

5.2x=-39+26

5.2x=-13

x=-13/5.2

x=2.5

9) –3(2,1z – 4)– 4,2 = 1,2(– 5z+ 0,5)

-6.3z+12-4.2=-6z+0.6

-6.3z+6z=0.6-7.8

-0.3z=-7.2

z=-7.2/(-0.3)

=24

10) 6,4(2 – 3y) = 6(0,8y – 1) + 6,8

12.8-19.2y=4.8y-6+6.8

-19.2y-4.8y=0.8-12.8

-24y=-12

y=-12/(-24)

y=0.5

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