Răspuns:
Explicație pas cu pas:
a)x(y-5)=17
x=17 => y-5=1 => y=6
sau x=1 =>y-5=17 =>y=22
b)xy+5x=-13
x(y+5)=-13
x=1 => y+5=-13 => y=-18
sau x=-1 => y+5=13 => y=18
sau x=13 =>y+5=-1 =>y=-6
sau x=-13 => y+5=1 => y=-4
e) x^2+3x-2x-6=0
x(x+3)-2(x+3)=0
(x-2)(x+3)=0
x=2 sau x=-3
f)x^2+3x-4x-12=0
x(x+3)-4(x+3)=0
(x+3)(x-4)=0
x=-3 sau x=4
g)x^2-6x-16=0
x^2+2x-8x-16=0
x(x+2)-8(x+2)=0
(x-8)(x+2)=0
x=8 sau x=-2