( x - 25) x 17 = 34
=> x - 25 = 34 : 17
x - 25 = 2
=> x = 2 + 25
x = 27
145 + (150 - x) = 250
=> 150 - x = 250 - 145
150 - x = 105
=> x = 150 - 105
x = 45
(2x - 7) x 81 = 0
=> 2x - 7 = 0 : 81
2x - 7 = 0
=> 2x = 7
=> x = 7 : 2 = 3,5
x - 90 : 15 = 32
=> x - 6 = 32
=> x = 32 + 6
x = 38
520 - (x - 5) = 250 : 5
=> 520 - (x - 5) = 50
=> x - 5 = 520 - 50
x - 5 = 470
=> x = 470 + 5
x = 475
t i c k nhé!! 346457567684786896789
a ) \(\left(x-5\right).17=34\)
=> \(x-5=2\)
=> \(x=7\)
b ) \(145+\left(150-x\right)=250\)
=> \(150-x=105\)
=> \(x=150-105\)
=> \(x=45\)
c ) \(\left(2.x-7\right).81=0\)
=> \(2x-7=0\)
=> \(2x=7\)
=> \(x=\frac{7}{2}\)
d ) \(x-90:15=32\)
=> \(x-6=32\)
=> \(x=38\)
Mấy cái dấu chấm đó là nhân đó nhé