a) 50x+15+3-9x=40x+20+3
41x+18=40x+23
41x-40x=23-18
x=5
b) 15x-21+4x+34=15x-20+37
19x+13=15x+17
19x-15x=17-13
4x=4
x=1
c) 24x-16-13x=60-15x+7x-19
11x-16=-8x+41
11x+8x=41+16
19x=57
x=3
d) 34-51x+25x-30=12-32x+10
-26x+4=-32x+22
-26x+32x=22-4
6x=18
x=3
e) 10x+15x-35+27-18x=4x+10+15
7x-8=4x+25
7x-4x=25+8
3x=33
x=11
f) 30x-24+40-15x=6x+21+22
15x+16=6x+43
15x-6x=43-16
9x=27
x=3
g) 12x-54+80-6x=6x+15+11
6x+26=6x+26
x=0