帮我解几道方程、、8x-4（10-x）=44 60x+(100-x)*65=100*63 30x-20(180-x)=5250 0.4x+0.2(99-x)=34 4x+3(x+8)=164 (x+6)*4+(x+x+6)*10=660 每步都写清楚点 please!

8x-4（10-x）=44
8x-40+4x）=44
12x=84
x=7
60x+(100-x)*65=100*63
60x+6500-65x=6300
5x=200
x=40
30x-20(180-x)=5250
50x=5250+3600
x=177
0.4x+0.2(99-x)=34
0.2x=14.2
x=71
4x+3(x+8)=164
7x=140
x=20
(x+6)*4+(x+x+6)*10=660
4x+24+20x+60=660
24x=576
x=24