Question

Do I start this by subtracting?

Answer 1

`\bf PQ\implies \ \textless \ 7-5,3-4\ \textgreater \ \implies \ \textless \ 2,-1\ \textgreater \ \\\\\\ RS\implies \ \textless \ 4-8,1-6\ \textgreater \ \implies \ \textless \ -4,-5\ \textgreater \ \\\\\\ 3RS\implies 3\ \textless \ -4,-5\ \textgreater \ \implies \ \textless \ 3\cdot -4,3\cdot -5\ \textgreater \ \implies \ \textless \ -12,-15\ \textgreater \ \\\\\\ \overrightarrow{PQ}+3\overrightarrow{RS}\implies \ \textless \ 2,-1\ \textgreater \ +\ \textless \ -12,-15\ \textgreater \ \\\\\\ \ \textless \ 2-12,-1-15\ \textgreater \ \implies \boxed{\ \textless \ -10,-16\ \textgreater \ }\\\\ -------------------------------\\\\ magnitude \\\\\\ √((-10)^2+(-16)^2)\implies √(100+256)\implies √(356)\implies \boxed{2√(89)}`