Question

[Phượng Phạm]

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

Answer 1

[Gia Hân]

$a)(x-25)-175=0$

$\to x-25=0+175=175$

$\to x=175+25$

$\to x=200$

Answer 2

[Gia Hân]

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

$\to 6.x+60=485-5=480$

$\to 6.x=480-60=420$

$\to x=420:6=70$