1) 9 (x+4) = 63 2) (y-6,5) : 7=0,5 3) (x+2/3) * 6=5,5 4) 8,4: (y-2) = 4

Найдем корни уравнений.

1) 9 * (x + 4) = 63;

x + 4 = 63/9;

x + 4 = 7;

x = 7 - 4;

x = 3;

2) (y - 6,5) / 7 = 0,5;

Умножим крест на крест.

y - 6.5 = 0.5 * 7;

y - 6.5 = 3.5;

y = 3.5 + 6.5;

y = 9;

3) (x + 2) / 3 * 6 = 5,5;

Сократим дробь.

(x + 2) * 2 = 5.5;

(x + 2) * 2 = 11/2;

4 * (x + 2) = 11;

4 * x + 4 * 2 = 11;

4 * x + 8 = 11;

4 * x = 11 - 8;

4 * x = 3;

x = 3/4;

x = 0.75;

4) 8,4 / (y - 2) = 4;

4 * (y - 2) = 8.4;

y - 2 = 8.4/4;

y - 2 = 2.1;

y = 2.1 + 2;

y = 4.1.