(x²+5x)²-2(x²+5x)=24 adunam 1 la ambii termeni
(x²+5x)²-2(x²+5x)+1=24+1 observam in stanga desfasuratul lui (a-b)²=a²-2ab+b²
unde a = x²+5x si b=1
(x²+5x-1)²=25
x²+5x-1=+/- 5
solutia
x²+5x-1= 5
x²-1+5x-5=0
(x+1)(x-1)+5(x-1)=0
(x-1)(x+1+5)=0
(x-1)(x+6) =0
x=1
x= - 6
solutia 2
x²+5x-1= -5
x²-1+5x+5=0
(x+1)(x-1)+5(x+1)=0
(x+1)(x-1+5)=0
(x+1)(x+4) =0
x=-1
x= -4
