Question

Write an equation for a line that passes through (-1,4) and is parallel to 2y + 10x=-36

Answer 1

Hi there Brook!

First, you need to find the slope of this linear line, because if two lines are parallel they have the same exact slope.

2y + 10x = -36  <-- Subtract 10x on both sides
2y = -10x - 36   <-- Divide everything by 2
y = -5x - 18  <-- Your re-organized linear equation, with the slope of -5.

Now that you know the slope is -5, but not the y-intercept since the line is different, look at the coordinate you have.  Since you know that an input of -1 makes an output of 4, you can create an equation:

4 = -5(-1) + b  <-- Four equals the slope times the input, plus the y-intercept
4 = 5 + b
b = -1, since 5 + (-1) = 4.

So, now your final equation is y = -5x -1