Tìm x

bài 15: tìm x

a) (x - 25 ) - 175 = 0

b) 485 - ( 6 . x + 60 ) = 5

c) ( x - 31 ) - 68 = 0

d) 274 - ( 9 . x + 18 ) = 4

e) 315 + ( 135 - x ) = 450

f) 346 + ( 210 - x ) = 556

g) 442 + ( 420 - x ) = 860

h) 107 + (320 - x ) = 317