Tik nha!!!
a) a)5(x+\(3^2\).5)=300.
➜ 5(x+14)=300
➜5x+70=300
➜5x=300-70
➜5x=230
➜X=46
Vậy..............................
a) 5(x+32.5)=300
x+32.5=300:5
x+32.5=60
x+32=12
x+9=12
x=3
b) 425+(121+x)=789
121+x=789-425
121+x=364
x=364-121
x=243