👤

2 x ( 2x + 1) + 5 = 5 x ( x - 1 ) please 50 puncte .

Răspuns :

2×(2x+1)+5=4x+7
5x(x-1)=5x-5
4x+7=5x-5=>4x-5x=-7-5=>-x=-12 / ÷ sau × =>x=12