1){x+2y=1 {2x-y= -8 2){3x-2y=2 {2x+y=1
х=1-2у y=1-2x
2*(1-2у)-у=-8 3x-2*(1-2x)=2
2-4у-у=-8 3x-2+4x=2
-5у=-8-2=-10 7x=2+2=4
у=2 x=4/7
2х-2=-8 2x+y=1
2х=-8+2 2*4/7+y=1
2х=-6 8+7y=7
х=-6/2 7y=7-8=-1
х=-3 y=-1/7
(2х-1)^2=2x-1
4x^2-4x+1=2x-1
4x^2-4x-2x+1+1=0
4x^2-6x+2=0-поделим на 2
2x^2-3x+1=0
D=(-3)^2-4*2*1=9-8=1
x1=-(-3)+1/2*2=1x2=-(-3)-1/2*2=1/2
(x-3)^2=4(x-3)
x^2-6x+9=4x-12
x^2-10x+21=0
D=(-10)^2-4*1*21=100-84=16
x1=10+4/2*1=7x2=10-4/2*1=3
4(x-3)^2=(2x+6)^2
4(x^2-6x+9)=4x^2+24x+36
4x^2-24x+36=4x^2+24x+36
4x^2-24x+36-4x^2-24x-36=0
-48x=0
x=0 пусть v-корень(3x+4)^2=3(x+4)
9x^2+24x+16=3x+12
9x^2+24x+16-3x-12=0
9x^2+21x+4=0
D=21^2-4*9*4=441-144=297
x1=-21+v297/2*9=-21+v297/18x2=-21-v297/2*9=-21-v297/18