Решите уравнение:

1) (5-2x) (7x-1) = (2x-5) ²

2) 3x³+5x²-10x-50=0

3) 2y³-5y²-2y+5=0

4) x⁴-25x²+60x-36=0

1) (5-2x) (7x-1) = (2x-5) ²

35x-5-14x²+2x-4x²+20x-25=0

-18x²+57x-30=0

6x²-19x+10=0

D=361-240=121

x1 = (19-11) / 12=2/3

x2 = (19+11) / 12=5/2

3) 2y³-5y²-2y+5=0

y² (2y-5) - (2y-5) = 0

(2y-5) (y²-1) = 0

2y-5=0

2y=5

y=2,5

y²-1=0

y²=1

y=-1

y=1

4) x⁴-25x²+60x-36=0

x^4 - (5x-6) ²=0

(x²-5x+6) (x²+5x-6) = 0

x²-5x+6=0

x1+x2=5 U x1*x2=6

x1=2 U x2=3

x²+5x-6=0

x1=x2=-5 U x1*x2=-6

x1=-6 U x2=1