1)
0,5(x-6)^2+2x(8-x/4)=2
0,5(x^2-12x+36)+16x-x^2/2=2
0,5x^2-6x+18+16x-x^2/2=2
0,5x^2+10x+18-0,5x^2=2
10x=2-18
10x=-16
x=-16/10=-1,6
2)
y+(5y+2)^2=25(2+y^2)
y+25y^2+20y+4=50+25y^2
21y+4=50
21y=46
y=46/21=2 4/21
1) (5x+1)^2-3(5x+1)-4=0
5x+1=t
t^2-3t-4=0
по Виету:
t1+t2=3
t1×t2=-4
t1=-1; t2=4
5x+1=-1
5x=-2
x1=-2/5=-0.4
5x+1=4
5x=5
x2=1
2) (x^2-7)^2-4(x^2-7)-45=0
(x^2-7)=t
t^2-4t-45=0
D=16+180=196=14^2
t1=(4+14)/2=18/2=9
t2=(4-14)/2=-10/2=-5
x^2-7=9
x^2=16
x1,2=+-4
x^2-7=-5
x^2=2
x2,3=+- √2
вроде так)