Question

Select the equations of the lines that are parallel to the line whose equation is y = 3x + 5.

6x + 2y = 12
-3x + y = 8
3y = 9x

Answer 1

-3x+y=8

3y=9x

Explanation:

Parallel lines have the same slope, so, our desire lines must comply the condition of m=-3, obtained from the slope of line y=3x+5

the line -3x+y=8, is equivalent to y=8+3x in its slope intersect form

the line 3y=9x can also, be written as y=3x by dividing by 3 both sides of equality sign.

The first seems at first glance that may be parallel as well, but when you write the equation in slope intersect form you get the slope is -3 (which is not same as the previous slopes).