1. 31a+48a+127=79a+127
a=4; 79*4+127=443
a=10; 79*10+127=917
2. a) 17x-4x=195
13x=195
x=15
b) 5x+23x=168
28x=168
x=6
c) (3x+10x)*8=312
24x+80x=312
104x=312
x=3
3. a) 98x-87x=594
11x=594
x=54
b)23x-12x+6x+5=90
17x=85
x=5
c) (16x-10x+3)*4=132
(6x+3)*4=132
24x+12=132
24x=120
x=5