A formula is given as $s=5r^{2}+3t$. Find the value of $s$ when $r=-2$ and $t=4$. [1] R

Question

A formula is given as $s=5r^{2}+3t$. Find the value of $s$ when $r=-2$ and $t=4$. [1] Rearrange the formula to make $r$ the subject. [2]

Accepted Answer

(a) $s=32$ (b) $r=\pm\sqrt{\frac{s-3t}{5}}$

Algebraic Expressions, Identities and Formulae