( 6x - 18 ) : 3 + 25 . 2 = 78
( 6x - 18 ) : 3 + 50 = 78
( 6x - 18 ) : 3 = 78 - 50
( 6x - 18 ) : 3 = 28
( 6x - 18 ) = 28 . 3
( 6x - 18 ) = 84
6x = 84 + 18
6x = 102
x = 102 : 6
x = 17
Vậy x = 17
(2x+1)^3=125
<=>2x+1=5 (vì là bậc 3 nên giữ nguyên dấu)
<=>2x=4
=>x=2
\(440+2x\left(125-x\right)=546\)
\(2x\left(125-x\right)=106\)
\(250x-2x^2-106=0\)
\(-\left(2x^2-250x+106\right)=0\)
cau nay qua kho voi hoc sinh lop 5
\(\left(6x-18\right):3+25.2=78\)
\(2x-6+50=78\)
\(2x=78+6-50\)
\(2x=34\)
\(x=17\)
vay \(x=17\)
