Question

Choose the equation of the line passing through the point (2, 6) and parallel to y = -3x - 4.

y = 3x - 12

y = -3x

y = -3x + 12

y = 3x


Algebra 1 problem I'm stuck on

Answer 1

To work such a problem, put the original line in slope-intercept form (\(y = mx + b\)) if not already there. Then you can read out the slope \(m\). Parallel lines will have identical slope.

Next, take the known point \((x_0,y_0)\) and use it in the point-slope formula for a line with slope \(m\) passing through the point \((x_0,y_0)\) to write the equation for the new line. Point-slope formula is\[y-y_0=m(x-x_0)\]
Then do any rearrangement necessary to get it in the form desired by the problem, and you're done.

Answer 2

In this case, you can take a shortcut — just look for equations with the same slope, and see if they are true if you plug in the point (2,6). I would recommend you go through the motions of actually finding the equation, however; do this until it is second nature before you start "gaming" the problems.

Answer 3

I got the answer thanks alot!!

Answer 4

Great!

Answer 5

Not so hard once you know what to do...

Answer 6

Excuse me but does the same apply for perpendicular?

Answer 7

yes, except with perpendicular lines, the product of the slopes = -1

there's one exception: if one line is horizontal or vertical, that doesn't apply, because a vertical line has an undefined slope. you have to just recognize that case from the fact that one line looks like \(x=<constant>\) or \(y = <constant>\)

Answer 8

Okay, Thank you.