(4x-3y)²-(2x+y)(3x-5y)=16х²-24ху+9у²-6х²+10ху-3ху+5у²=10х²+14у²-11ху
25х³у²-4ху⁴=ху²(25х²-4у²)=ху²(5х-2у)(5х+2у)
45-30а+5а²=5(9-6а+a²)=5(3-a)(3-a)
(2x-3)(2x+3)=4x(x+1)-1
4x²-9=4x²+4x-1
x=-2
(4x+y=-10
(5x-2y=-19
y=-10-4x
5x+20+8x=-19
13x=-39
x=-3
y=-10+12=2