Question

Write the equation in standard form of the line that passes through (-1,-4) parallel to 9x -y = 4

Answer 1

9x-y=-5

Explanation:

First, put this equation into slope intercept form (makes it easier)

9x-y=4

subtract 9x from both sides

-y=-9x+4

multiply by -1 on both sides

y=9x-4

Parallel lines have the same slopes, so the second line is y=9x+b (b is a placeholder for the y intercept)

now, find the y intercept

since the line has to go through (-1,-4), plug it into the equation

-4=9(-1)+b

-4=-9+b

5=b

so now the line would be y=9x+5... in slope intercept form. The question asks for the answer to be in standard form.

5 from both sides

y-5=9x

subtract y from both sides

-5=-y+9x

or

9x-y=-5