Question

Tìm x biết:
a) (50 − x) + 12 = 31 ; b) 75 ∶ (x − 2) + 4 = 7 ;
c) 125 − 3(x + 3) = 65 ;

Answer 1

a) (50 - x ) +12 =31
- x + 62 = 31
- x = - 31
x = 31

b) 75 . ( x - 2 ) + 4 = 7
75x - 150 + 4 = 7
75x - 146 = 7
75x = 153
75x/75 = 153/75
x = 51/25
x = 2 1/25

c) 125 -3(x + 3 ) = 65
125 -3x - 9 = 65
3x + 116 = 65
3x = - 51
x = - 17