solve 12ab = 4 for a. solve xm = x + z for x. solve p = 2l + 2w for w.

Explanation:

Step1: Isolate the variable $a$

Divide both sides of $12ab = 4$ by $12b$ (assuming $b\neq0$). So, $\frac{12ab}{12b}=\frac{4}{12b}$.

Step2: Simplify the right - hand side

$\frac{4}{12b}=\frac{1}{3b}$, so $a = \frac{1}{3b}$.

Step3: Isolate the variable $x$ in $xm=x + z$

Subtract $x$ from both sides: $xm - x=z$.

Step4: Factor out $x$

$x(m - 1)=z$.

Step5: Solve for $x$

Divide both sides by $(m - 1)$ (assuming $m\neq1$), $x=\frac{z}{m - 1}$.

Step6: Isolate the variable $w$ in $P = 2l+2w$

Subtract $2l$ from both sides: $P - 2l=2w$.

Step7: Solve for $w$

Divide both sides by $2$, $w=\frac{P - 2l}{2}$.

Answer:

$a=\frac{1}{3b}$ $x=\frac{z}{m - 1}$ $w=\frac{P - 2l}{2}$