a)(x-13)-17=0
=>X-13. = 0+17
=>x-13. =17
=>x. = 17+13
=>x. = 30
b)315+(125-x)=435
=>(125-x). =435-315
=>(125-x). =120
=>.x. = 5
c)575-(6x+70)=445
=>(6x+70). =575-445
=> (6x+70). =130
=>. 6x. =130-70
=>6x. =60
=>x. =60:6
=>X. =10
a) (x-13)-17=0 (x-13) =0+17 x-13 =17 x = 17+13 x =30
d)(x-105):21=15
=>(X-105). =15.21
=>(x-105). =315
=>x. = 315+105
=>x. =420
e)102-3.(x+1)=27
=> 3.(x+1.) =102-27
=>3.(x+1) =75
=>x+1. =75:3
=>x+1. =25
=> x. = 25-1
x. =24
chị Girl cá tính lm đúng rùi nhé
a. ( x - 13 ) -17 = 0
x-13=0+17
x-13=17
Vậy x=30
b. 315 + (125-x) = 435
125-x=435-315
125-x=120
x=125-120
x= 5
Vậy x=5
c. 575-(6x+70)=445
6x+70=575-445
6x+70=130
6x=130-70
6x=60
x=60:6
x=10
Vậy x=10