evaluate:
x^2+y^3 if x=2 y=-3
4+-27=-23
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pm^2-z^3 if p=1 m=-4 z=-2
(1)(-4^2)-(-2)^3=(1)(16)-(-8)=16+8=24
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-x^2-y^3 if x=-3 y=-2
-3^2-2^3
-9-8=-17
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a^2-b^2a if a=-2 b=3
-2^2-3^2
-4-9-2=-13-2=-15
If not correct please explain step by step what I did wrong so I can get the hang of this thanks :)