a)x+4=198-120
x+4=78
x =78-4
x =74
b)2(x-51)=36
x-51 =36:2
x =18+51
x =69
c)x-19=450:50
x =9+19
x =28
d)4(x-3)=48
x-3 =48:4
x =12+3
x =15
a: \(\Leftrightarrow x+4=78\)
hay x=74
b: \(\Leftrightarrow x-51=2^3+10=18\)
hay x=69
a) 198 – (x + 4) = 120
x+4=198-120
x+4=78
x=78-4
x=74
vậy x=74
b) 2(x- 51) = 2.23 + 20
2(x- 51) = 2.8 + 20
2(x- 51) = 16 + 20
2(x-51)=36
x-51=36:2
x-5=13
x=13+5
x=18
vậy x=18
c) 450 : (x – 19) = 50
x-19=450:50
x-19=9
x=9+19
x=28
vậy x=28
4(x – 3) = 72 – 110
4(x – 3) =49-1
4(x-3)=48
x-3=48:4
x-3=12
x=12+3
x=15
vậy x=15