a, 7 x ( x - 11 ) - 6 = 757
7 x ( x - 11 ) = 757 + 6
7 x ( x - 11 ) = 763
( x - 11 ) = 763 : 7
x - 11 = 109
x = 109 + 11
x = 120
Vậy x = 120
7 x ( x -11 ) - 6 = 757
7 x ( x - 11 ) = 757 + 6
7 x ( x - 11 ) = 763
( x- 11 ) = 763 : 7
x - 11 = 109
x = 109 + 11
x = 120
a) 7 x (x - 11) - 6 = 757
7 x (x - 11) = 757 + 6
7 x (x - 11) = 763
x - 11 = 763 : 7
x - 11 = 109
x = 109 + 11
x = 120
b) a x X = aaa
X = aaa : a
X = 111