Question

-3x 2 + 2y 2 + 5xy - 2y + 5x 2 - 3y 2 if x=2 and y=-1

Answer 1

if
`x=2,y=1` the formula becomes:

`-3(2)^2 + 2*1^2 + 5(2) - 2 + 5(2)^2 - 3*1^ 2\\=(-12+2)+(10-2)+(20-3)\\=(-10+8)+17\\=-2+17\\=15`