Question

Passes through (-1, 7) and PERPENDICULAR to x-3y = 15

Answer 1

3x + y = 4 OR y = -3x + 4

Explanation:

We can find the second slope of perpendicular line using the formula,

`m_(2)=-(1)/(m_(1))`

The line x - 3y = 15 is in standard form (Ax + By = C), but we can convert it to slope-intercept form (y = mx + b) to find m1:

`x-3y=15\\-3y=-x+15\\y=1/3x-5`

Since we've found that m1 = 1/3, we can now find m2:

`m_2=-(1)/((1/3))\\ m_2=-3`

We can find the y-intercept of the second line by plugging in the points we're given and the slope and solving for b:

`7=-3(-1)+b\\7=3+b\\4=b\\`

If you're teacher requires you to use the standard form of the line, you can convert from slope-intercept form to standard form by simply adding 3x:

`y=-3x+4\\y+3x=4`