\(\left(x-27\right)\cdot91-72=215\cdot91-72\)
\(\left(x-27\right)\cdot91=215\cdot91-72+72\)
\(\left(x-27\right)\cdot91=215\cdot91\)
\(\left(x-27\right)=215\cdot91:91\)
\(x-27=215\)
\(x=242\)
\(\left(x-27\right).91-72=215.91-72\)
Do 2 đẳng thức trên bằng nhau nên rút gọn 2 vế với - 7 ta đc
\(\Rightarrow\left(x-27\right).91=215.91\)
\(\Rightarrow\left(x-27\right)=215\)
\(\Rightarrow x=215+27=242\)
(x-27).91-72 = (215).91-72
=> (x-27).91 - 72 + 72= (215).91
(x-27).91 = (215).91 ( chia cả 2 vế cho 91)
=> x - 27 = 215
x = 242
\(\left(x-27\right).91-72=215.91-72\)
\(\Rightarrow\left(x-27\right).91=215.91\)
\(\Rightarrow x-27=215\)
\(\Rightarrow x=242\)
hok tốt!
(x-27).91-72 = (215).91 - 72
=> (x-27).91 - 72 + 72 = (215).91
(x-27).91 = (215).91
=> x - 27 = 215
x = 242
( x - 27 ) . 91 - 72 = 215 . 91 - 72
( x - 27 ) . 91 = 215 . 91 - 72 + 72
( x -27 ) . 91 = 215 . 91
x - 27 = 215 . 91 : 91
x - 27 = 215
x = 242
Vậy x = 242
