Question

Determine whether the lines are parallel or perpendicular or neither. 2x=y−10 and y=−2x

Answer 1

Put the first equation in slope-intercept form, or y = mx + b. Start by subtracting y from both sides.

2x - y = -10, subtract 2x from both sides.

-y = -10 - 2x

Divide both sides by negative one.

y = 10 + 2x

To find the slope when the equations are in slope-intercept form you look at the coefficient of x. The first equation has the slope of 2 (which we just found), and the second equation has the slope of -2.

Parallel lines have the same slope and perpendicular lines have opposite reciprocal slopes. Since 2 and -2 are neither of these, your answer is neither.