решите уравнения 1)4 х -х=8 7 2)а+а+8154=32 3)7к-4к-55,2=63,12

Найдем корешки.

1) 4 * х - х = 87; 

x * (4 - 1) = 87; 

x  * 3 = 87;

x = 87/3;

x = 60/3 + 27/3;

x = 20 + 9;

x = 29.

2) а + а + 8 154 = 32; 

a * (1 + 1) + 8 154 = 32;

2 * a + 8 154 = 32;

2 * a = 32 - 8 154;

2 * a = -8 122;

a = -8 122/2;

a = -4 000 - 50 - 11;

a = - 4 061.

3) 7 * k - 4 * k - 55,2 = 63,12; 

3 * k - 55.2 = 63.12; 

3 * k = 63.12 + 55.2; 

3 * k = 118.32; 

k = 118.32/3; 

k = 39.44.