Question

What is the slope of a line parallel to the line whose equation is 3x + 6y = 9?

A. -1/2
B. 1/2
C. 2
D. 3

Answer 1

C

Explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Rearrange 3x + 6y = 9 into this form

Subtract 6x from both sides

6y = - 3x + 9 ( divide all terms by 6 )

y = -
`\frac1}{2}` x +
`(3)/(2)` ← in slope- intercept form

with slope m = -
`(1)/(2)`

Given a line with slope m then the slope of a line perpendicular to it is

`m_(perpendicular)` = -
`(1)/(m)` = -
`(1)/(-(1)/(2) )` = 2 → C

Answer 2

The answer is A: -1/2