(4x - 28) : 2 = 9² - 65
(4x - 28) : 2 = 81 - 65
(4x - 28) : 2 = 16
4x - 28 = 16 . 2
4x - 28 = 32
4x = 32 + 28
4x = 60
x = 60 : 4
x = 15
(4\(x\) - 28) : 2 = 92 - 65
(4\(x\) - 28 ) : 2 = 81 - 65
(4\(x\) - 28) : 2 = 16
4\(x\) - 28 = 16 x 2
4\(x\) - 28 = 32
4\(x\) = 32 + 28
4\(x\) = 60
\(x\) = 60 : 4
\(x\) = 15
(4x-28):2=81-65=16
(4x-28)=16 nhân 2 =32
(4x)=32+28=60
x=60:4=15