Question

8)What is the equation of a line that goes through the point (3, 12) and is perpendicular to the line given by the equation y = -1/3x - 7?

(A) y = -3x - 12
(B )y = -1/3x + 6
(C) y = 3x + 3
(D) = (1/3x) - 6

Answer 1

The slope of the first line is
`m_1=(-1)/(3)`.
To be perpendicular the slope of the second line must be the negative reciprocal of the first:
`m_2=3`
Use the slope-intercept formula:

`y=mx+b`
Substitute known values:

`12=3(3)+b`
Solve for
`b`:

`b=3`
Complete the formula:

`y=3x+3`