Why does it make sense that the slipe of perpendicular lines have oppposite signs?

These lines are perpendicular since their slopes are negative reciprocals. If you multiply a slope times its negative reciprocal, the result is always -1. ... Let's prove that perpendicular lines have negative reciprocal slopes, AND that negative reciprocal slopes imply perpendicular lines.

it's d.

step-by-step explanation:

because: -1(4x + 1y) +2 (1x-3y) distribute each number into the parenthesis.

then you would get: -4x - 1y + 2x -6y combine like terms

and get: 2x -7y

hope my answer has you if not then i'm sorry.