5(4+6x)=290
5.4 + 5. 6x=290
20+ 30x =290
30x= 290-20
30x=270
x=9
5 x ( 4 + 6 . x ) = 290
4 + 6 . x = 290 : 5
4 + 6 . x = 58
6 . x = 58 - 4
6 . x = 54
x = 54 : 6
x = 9
Vậy x = 9
5 x ( 4 +6 x X ) = 290
4 + 6 x X = 290 : 5
4 + 6 x X = 58
6 x X = 58 -4
6 x X = 54
X =54 : 6
X = 9
hok tốt