Suppose your friend says the line y=-2x + 3 is perpendicular to the line x+2y=8. Do you agree? Explain.

If they are perpendicular then the product of their slope will = - 1

y = 2x + 3 has slope of 2 (because of the '2x')

x + 2y = 8

2y = - x + 8

y = - 0.5x - 4

2 * - 0.5 = - 1 so they are perpendicular

So the friend was right

No because if they were perpendicular their slopes would be opposite reciprocals