First, try rewriting all of the subtraction as addition, then attempt to solve by combining like terms.

$3p+(-7)+9+(-2p)=p+2$
$p+2=p+2$
$p=p$

Since $p=p$ (or $2=2$, depending on how you solved the problem), $p$ can equal any number.

Refer to parts (a) and (d).

Refer to parts (a) and (d).

One strategy is to rewrite all of the subtraction within the problem as addition.
$-y^2+2=y^2+-5+-2y^2$

Now simplify, starting with combining like terms and then isolating the variable.

$-y^2+2=-y^2+-5$
$2=-5$

No solution because $2$ is not equal to $-5$.