Question

Write the equation of a line that is perpendicular to y=-2/7x + 9 and that passes through the point (4,-6)

Answer 1

a line that is perpendicular to a given line will have a slope of -1/m
so we have y = -7/2 x + (the y intercept)
given the point (4,-6)
-6 = -14 + 8 (the y intercept)
so the equation is y = -7/2 x + 8

Answer 2

• y = 3.5x - 20

Explanation:

The line perpendicular to the given has a negative reciprocal slope:

• m = 7/2

Use point-slope form to find the y-intercept and the equation:

• y - y₁ = m(x - x₁), where (x₁, y₁) is the given point
• y - (-6) = 7/2(x - 4)
• y = 7/2x - 14 - 6
• y = 7/2x - 20

or

• y = 3.5x - 20