Which of the following lines is parallel to the line y=3x+5 and contains the point (1,1)

Question

A. 3x-y+5=0

 

B. X+3y-4=0

 

C. 3x-y-2=0

 

D. 12x-6y=6=0

Answer 1

Change each of the equations given to slope-intercept form. Then compare the slopes to the slope in the given equation. The slope of a line parallel to the given line will have a slope equal to the slope of the given line. Then check if the line goes through (1,1) by substituting (1,1) into the equation for the parallel line.

 

 

select: B to check:

 

1. Convert to slope-intercept form y=mx+b.

 

x+3y-4=0        Add 4 to both sides.

 

x+3y=4           Subtract (x) from both sides.

 

3y=-x+4          Divide both sides by 3.

 

y=-x/3+4/3      Notice the slope (-1/3) is the negative-inverse of the slope 3 in the given equation. The lines are perpendicular.

 

Check equation C using the same method and you get y=3x-2. Check that it goes through point point (1,1)

 

y=3x-2

(1)=3(1)-2 1=3-2=1 Chose equation C.

Answer 2

Hint:

 

To be parallel it has to have a slope of 3 (y=3x+5 has a slope of 3) and when you plug in 1 for x the correct solution has a solution of y=1.