Answer:
[tex]^{\to}_{PQ}+4^{\to}_{RS}=<\:-14,-21\:>\:[/tex]
[tex]|^{\to}_{PQ}+4^{\to}_{RS}|=7\sqrt{13}[/tex]
Step-by-step explanation:
The given points have coordinates; P=(5,4), Q=(7,3), R=(8,6), and S=(4,1).
[tex]^{\to}_{PQ}=^{\to}_{OQ}-^{\to}_{OP}[/tex]
[tex]^{\to}_{PQ}=<\:7,3\:>\:-\:<\:5,4\:>[/tex]
[tex]^{\to}_{PQ}=<\:7-5,3-4\:>\:[/tex]
[tex]^{\to}_{PQ}=<\:2,-1\:>\:[/tex]
[tex]^{\to}_{RS}=^{\to}_{OS}-^{\to}_{OR}[/tex]
[tex]^{\to}_{RS}=<\:4,1\:>\:-\:<\:8,6\:>[/tex]
[tex]^{\to}_{RS}=<\:4-8,1-6\:>\:[/tex]
[tex]^{\to}_{RS}=<\:-4,-5\:>\:[/tex]
[tex]^{\to}_{PQ}+4^{\to}_{RS}=<\:2,-1\:>\:+4\:<\:-4,-5\:>\:[/tex]
[tex]^{\to}_{PQ}+4^{\to}_{RS}=<\:2,-1\:>\:+\:<\:-16,-20\:>\:[/tex]
[tex]^{\to}_{PQ}+4^{\to}_{RS}=<\:2-16,-1-20\:>\:[/tex]
[tex]^{\to}_{PQ}+4^{\to}_{RS}=<\:-14,-21\:>\:[/tex]
The correct answer is C
The magnitude is given by:
[tex]|^{\to}_{PQ}+4^{\to}_{RS}|=\sqrt{x^2+y^2}[/tex]
[tex]|^{\to}_{PQ}+4^{\to}_{RS}|=\sqrt{(-14)^2+(-21)^2}[/tex]
[tex]|^{\to}_{PQ}+4^{\to}_{RS}|=\sqrt{196+441}[/tex]
[tex]|^{\to}_{PQ}+4^{\to}_{RS}|=\sqrt{637}[/tex]
[tex]|^{\to}_{PQ}+4^{\to}_{RS}|=7\sqrt{13}[/tex]
The correct answer is B