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
y = -1/3x

Answer 1

Parallel lines have equal gradients;
i) 6x + 2y=12
3x+y=6

ii) -3x+y=8
y=3x+8

iii) 3y=9x
y=3x

Answer 2

Parallel lines should have the same slope. In the equation of the line, Ax + By + C = 0. The slope of the line is calculated by dividing the negative of A by B. The slope of the line given is 3. Below, I listed the slopes.

(1) m = -6/2 = -3
(2) m = 3/1 = 3
(3) m = 9/3 = 3
(4) m = -1/3

Thus, the answers are the 2nd and 3rd choices.