Răspuns:
(x+1)²+x²-5(x-1)²=2(x-4)
x²+x²-5(x²-2x+1)=2x-8
2x²-5x²+10x-5=2x-8
-3x²+10x-5-2x+8=0
-3x²+8x+3=0║·(-1)
3x²-8x-3=0
Formula pe jumate
b`=b/2= -8/2=-4
Δ `=(b`)²-ac
x1/2=(-b`±√Δ`)/a
Δ`=(_4)²-·3·(-3)=
16+9=25
x1=(4-√25)/3=
(4-5)/3= -1/3
x2=(4+√25)/3=(4+5)/3=9/3
x2=3
Explicație pas cu pas: