2a+4=a+12 10c-4=8c+18 11y-8=3y+16 73-58e=169-64e 6*(b-3)=10-2*(b+2) 83+5*(y-3)=3*(8y-9)

1) 2a + 4 = a + 12;

2a - a = 12 - 4;

Соберем неведомые с одной стороны, а знаменитые - с иной:

a = 8.

2) 10c - 4 = 8c + 18;

10c - 8c = 18 + 4;

2c = 22;

c = 22 : 2;

c = 11.

3) 11y - 8 = 3y + 16;

11y - 3e = 16 + 8;

8y = 24;

y = 24 : 3;

y = 3.

4) 73 - 58e = 169 - 64e;

-58e + 64e = 169 - 73;

6e = 96;

e = 96 : 6;

e = 16.

5) 6 * (b - 3) = 10 - 2 * (b + 2);

Сначала раскроем скобки:

6b - 18 = 10 - 2b - 4;

6b - 18 = 6 - 2b;

6b + 2b = 6 + 18;

8b = 24;

b = 24 : 8;

b = 3.

6) 83 + 5 * (y - 3) = 3 * (8y - 9);

83 + 5y - 15 = 24y - 27;

5y + 68 = 24y - 27;

5y - 24y = -27 - 68;

-19y = -65;

y = -95 : (-19);

y = 5.