Bài 1:
a)5(2x-3)-4(5x-7)=19-2(x-11)
10x-15-20x+28=19-2x+22
10x-20x+2x =19+22+15-28
-8x =28
x =-7/2
b)4(x+3)-7x+17=8(5x-1)+166
4x+12-7x+17=40x-8+166
4x-7x-40x =-8+166-12-17
-43x =129
x =-3
c)17-14(x+1)=13-4(x+1)-5(x-3)
17-14x-14=13-4x-4-5x+15
-14x+4x+5x=13-4+15-17+14
-5x =21
x =-21/5
d)5x+3,5+(3x-4)=7x-3(x-0,5)
5x+3,5+3x-4 =7x-3x+1,5
5x+3x+3x-7x =1,5-3,5+4
4x =2
x =2/4