Решите уравнение 1) 9b+6b-15=615 2) 2 а+123 а = 97=472 3) 17 х-х+5 х-19=170 4) 73 у-у - 22 у+40=190 и сделайте проверку

1) 9b + 6b - 15 = 615;

15 * b - 15 = 615;

15b - 15 = 615;

15b = 615 + 15;

15b = 630;

b = 630 : 15;

b = 42.

9 * 42 + 6 * 42 - 15 = 615;

378 + 6 * 42 - 15 = 615;

378 + 252 - 15 = 615;

615 = 615.

2) 2 а + 123 а = 97;

125 * а = 97;

125 а = 97;

а = 97 : 125;

а = 0,776.

2 * 0,776 + 123 * 0,776 = 97;

1,552 + 95,448 = 97;

97 = 97.

2 а + 123 а = 472;

125 * а = 472;

125 а = 472;

a = 472 : 125;

a = 3,776.

2 * 3,776 + 123 * 3,776 = 472;

7,552 + 464,448 = 472;

472 = 472.

3) 17 х - х + 5 х - 19 = 170;

16x + 5x - 19 = 170;

21x = 170 + 19;

21x = 189;

x = 189 : 21;

x = 9.

17 * 9 - 9 + 5 * 9 - 19 = 170;

153 - 9 + 45 - 19 = 170;

170 = 170;

4) 73 у - у - 22 у + 40 = 190;

50y + 40 = 190;

50y = 190 - 40;

50y = 150;

y = 150 : 50;

y = 3.

73 * 3 - 3 - 22 * 3 + 40 = 190;

219 - 3 - 66 + 40 = 190;

190 = 190.