Уравнение. 84a+25a+7=443. 4(9+7x)21=393. 486:(5x+2)=18. 5(14+ b)+6b=258

1. 84 * a + 25 * a = 443 7;

109 * a = 436;

a = 436/109 (по пропорции);

a = 4.

2. 4 * 9 + 4 * 7 * x + 21 = 393;

36 + 28 * x + 21 = 393;

28 * x = 393 36 21;

28 * x = 336;

x = 336/28 (по пропорции);

x = 12.

3. (5 * x + 2) * 18 = 486 * 1 (по пропорции);

5 * x * 18 + 2 * 18 = 486;

90 * x + 36 = 486;

90 * x = 486 36;

90 * x = 450;

x = 450/90 (по пропорции);

x = 5.

4. 5 * 14 + 5 * b + 6 * b = 268;

70 + 5 * b + 6 * b = 268;

5 * b + 6 * b = 268 70;

11 * b = 198;

b = 198/11 (по пропорции);

b = 18.