Решите 5 уравнений: 1) 7a = - 310 + 3a 2) 25 - 3b = 9 - 5b 3) 3(4x- 8) = 3x - 6 4) 12 -...

Question

Решите 5 уравнений: 1) 7a = - 310 + 3a 2) 25 - 3b = 9 - 5b 3) 3(4x- 8) = 3x - 6 4) 12 - 2(x+ 3) = 26 5) - 5(0, 8 x - 1, 2) = - x + 7,2

Answer 1

1)  7a = - 310 + 3a

4a=-310

a=-77.5

2) 25 - 3b = 9 - 5b

2b=9-25

2b=-16

b=-8

3) 3(4x- 8) = 3x-6

12x-24=3x-6

9x=18

x=2

4) 12 - 2(x+ 3) = 26

12-2x-6=26

2x=12-6-26

2x=-20

x=-10

5) - 5(0, 8 x - 1, 2) = - x + 7,2

-4x+6=-x+7.2

3x=-1.2

x=-0.4