1)х²-4х-32=0 2)х^5*у7-х^3у^9/b^3y7 х=0,2; у=0,5

1) x²-4х-32=0   x1=8   x2=-4  по т. Виета  
2)х^5*у7-х^3у^9/x^3y7
Х=0,2;у=0,5

х^5*у7-х^3у^9/x^3y^7=х^3*у^7(x²-y²)/x^3*y^7=x²-y²
x²-y²=0.2²-0.5²=0.04-0.25=-0.21