Tìm x, biết: a) |x + 9|.2 = 10; b) 3x - 15 - x = 17; c) 15 - (x - 7) = -21

Bài 1:
a, |x+9|.2=10
b, 3x-15-x=17
c, 15-(x-7)=-21
d, |2x|-35=15
e, 3x-5=-7-13
g, 5(x-1)=4(x+2)