Question

Find the equation of the line.

The line is perpendicular to y = 1/2x +5 and passes through the point (4,7).

The equation of the line is: y =

Answer 1

y=-2x+15

Explanation

A perpendicular line always has the opposite reciprocal slope of the line it is 90 degrees from.

Since the slope of the other line is 1/2, the slope of this line must be -2. And with the slope of a line -2 with point (4,7), you can start plugging in numbers.

y=-2x+b

7= -2(4)+b

7= -8+b

15=b

Therefore, the equation of the line is y=-2x+15