x . (5 - 2x) + 2x . (x - 1) = 15
5x - 2x2 + 2x2 - 2x = 15
(5x - 2x) + (2x2 - 2x2) = 15
3x = 15
x = 15 : 3
x = 5
x.(5-2x)+2x.(x-1)=15
<=>5x-2x2+2x2-2x=15
<=>3x=15
<=>x=5
Ta có: \(x\left(5-2x\right)+2x\left(x-1\right)=15\)
<=> \(5x-2x^2+2x^2-2x=15\)
<=> \(3x=15\)
<=>x=15
1) x . ( 5 - 2 x ) + 2 x . ( x - 1 ) = 15
=> 5x - 2x2 + 2x2 - 2x = 15
=> ( 5x -2x ) + ( 2x2 - 2x2 ) = 15
=> 3x = 15
=> x = 15 :3
=> x = 5