Question

Determine whether the graphs of the given equations are perpendicular

3x + 5y = 10
5x – 3y = -6

Answer 1

Explanation:

For the two lines to be perpendicular one must it's gradient to be the negative reciprocal of the other;

3x + 5y = 10

5y = 10 - 3x

y = 2 - 3/5x

gradient = -3/5

5x - 3y = -6

5x + 6 = 3y

5/3x + 2 = y

gradient = 5/3

since the second line has the negative reciprocal of the first line, hence they are perpendicular.