Question

solve the equation $p = r + s + t$ for $r$.
$r = \square$ (simplify your answer.)

Explanation:

Step1: Isolate r by subtracting s+t

$P - (s + t) = r + s + t - (s + t)$

Step2: Simplify the right-hand side

$r = P - s - t$

Answer:

$r = P - s - t$