X-y=7
xy=-10
x=7+y
(7+y)y=-10
7y+y^2=-10
y^2+7y+10=0
D=7^2-4*1*10=3^2
y=(-7+3)/2=-2
y=(-7-3)/2=-5
x=5
x=2
<span>7x-(x+3)=3(2x-1)
7х-х-3=6х-3
6х-3=6х-3
6х-6х=-3+3
0х=0
х-любое</span>
<span>4x^2 -2x-1=0
4x^2 - 2x= -1
2x= -1
x= -1\2
x= -0,5
</span>
а) 2xy-6y^2=<span>-2y*(3y-x)</span>
б) a^3-4a=<span>(a-2)*a*(a+2)</span>
а) a^2b-ab^2=<span>-ab*(b-a)</span>
б) 9x-x^3=<span>(3-x)*x*(x+3)</span>