Question

Which equation represents a line through (-4, 3) that is perpendicular to y=x+7?

A. y=x+1
B. y=-x-1
C. y=-x+ 1
D. y=x-1

Answer 1

B. y = -x - 1

Explanation:

Perpendicular lines have opposite reciprocal slopes, so the slope of the new line will be -1.

Plug the slope and the given point into y = mx + b to find b:

y = mx + b

3 = -1(-4) + b

3 = 4 + b

-1 = b

Then, plug this and the slope into y = mx + b

y = -x - 1

So, the correct answer is B, y = -x - 1