Find an equation for the line perpendicular to the line −4x−9y=2 having the same y-intercept as 6x−4y=9.

Answer 1

The y-intercept of 6x - 4y = 9 is found by substituting 0 for x. So, y = -9/4.

For the line -4x - 9y = 2, -9y = 4x + 2. So, y = (-4/9)x - 2/9. The slope is -4/9.

Perpendicular slope is -1 / (-4/9) = 9/4.

Line with slope 9/4 and with y-intercept -9/4 is y = (9/4)x - 9/4, or equivalently -9x + 4y = -9.