Tìm x: a) x/8 = -1/4 b) 6 / x-3 = 9 / 2x-7 c) (x -1/2)^2 = 4

a) 

x8=−14x.4=−1.8x.4=−8x=−2

b)

6x−3=92x−76.2x−7=9.x−312x−42=9x−273x=15x=5

c)

x−122=4x−12=±2

TH1:

x−12=2x=52

TH2:

x−12=−2x=−32

 Vậy x=52 hoặc x=−32