Question

1146. Найдите корень уравнения:
1) 9 (х – 1) = x+ 15;
2) (11х + 14) — (5х – 8) = 25;
3) 12 - 4(x - 3) = 39 - 9x;
4) 2(3x + 5) - 3(4x - 1) = 11,8.​

Answer 1

1) 9 ( х - 1 ) = х + 15

9х - 9 = х + 15

9х - х = 15 + 9

8х = 24

х = 3

2) ( 11х + 14 ) - ( 5х - 8 ) = 25

11х + 14 - 5х + 8 = 25

11х - 5х = 25 - 8 - 14

6х = 3

х = 0.5

3) 12 - 4 ( х - 3 ) = 39 - 9х

12 - 4х + 12 = 39 - 9х

-4х + 9х = 39 - 12 - 12

5х = 15

х = 3

4) 2 ( 3х + 5 ) - 3 ( 4х - 1 ) = 11.8

6х + 10 - 12х + 3 = 11.8

6х - 12х = 11.8 - 10 - 3

-6х = -1.2

х = 0.2