Question

Find an equation of the the line satisfying the given conditions. Through (7, 2); perpendicular to 4x + 9y = 46 9x - 4y = 1 • 9x - 4y = 55 4x - y = 55 9x + 4y = 55

Answer 1

9x - 4y = 55

Explanation:

The equation for the perpendicular line can be written by swapping the x- and y-coefficients and negating one of them. Usually we choose to negate the one that makes the x-coefficient positive. Here, that process gives ...

9x - 4y = <some constant>

The value of the constant can be found by putting the (x, y) values of the given point into the left-side expression:

9x - 4y = 9·7 -4·2 = 55

9x - 47 = 55