2.x+3.x=430
=> x ( 2 + 3) = 430
=> x . 5 = 430
=> x = 430 : 5 = 86
75-5.x=30
=> 5x = 75 - 30
=> 5x = 45
=> x= 9
Vậy x = 9
2.x+3.x=430 75-5.x=30
2x+3x=430 75-5x=30
5x=430 5x=45
x=86 x=9
a, 2.x+3.x=430
x. (2+3) = 430
x. 5 =430
x = 430:x
x = 86
b, 75-5.x = 30
5.x = 75 - 30
5.x = 45
x = 45:5
x = 9
k cho mik nha ^^:)))
2.x+3.x=430
x.(2+3)=430
x.5=430
x=430:5
x=86
vậy x=86
75-5.x=30
5.x=75-30
5.x=25
x=25:5
x=5
vậy x=5
2 . x + 3 . x = 430
(2 + 3) . x = 430
5 . x = 430
x = 430 : 5
x = 86
75 - x . 5 = 30
x . 5 = 75 - 30
x . 5 = 45
x = 45 : 5
x 9