10-4(2x+5)=6y-13
4y-63=5(4x-2y)+2
4y-63-20x+10y-2=0
14y-65-20x=0
x=0.7y-3.25
3-8x-6y=0
3-8*(0.7y-3.25)-6y=0
3-5.6y+26-6y=0
29-11.6y=0
y=29/11.6y=2.пятых
14*2.5-65-20x=0
-30-20x=0
x=-30/20
x=-1.5
x(3x-2)=0
x1=0 3x-2=0
3x=2
x2=2/3
б). 2x^2+3x=x^2
2x^2+3x-x^2=0
x^2+3x=0
x(x+3)=0
x1=0 x+3=0
x2=-3
в). 2x^2-18=0
x^2-9=0
x^2=9
x=±3
г). 4x^2=9
x^2=9/4
x=±3/2
д). 3x^2-9=0
3x^2=9
x^2=3
x=±корень3
е). 5x^2+1=0
5x^2=-1
x^2=-1/5