If (-4, -5) is one vertex and \( \Large 7x-y+8=0 \) is one diagonal of a square then the equation of second diagonal is:


A) \( \Large x+3y=21 \)

B) \( \Large 2x-3y=7 \)

C) \( \Large x+7y=31 \)

D) \( \Large 2x+3y=21 \)

Correct Answer:
B) \( \Large 2x-3y=7 \)

Description for Correct answer:
Equation of perpendicular line to \( \Large 7x-y+8=0 \) is \( \Large x+7y=h \) which is passes through \( \Large \left(-4,\ 5\right) \)

h = 31

So, equation of another diagonal is \( \Large x+7y=31 \)

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