123k views
0 votes
Are the lines parallel, perpendicular or neither.a. 3x − 4y = −2; 4y = 3x − 12b. 8x − 2y = 7; 3x + 12y = 9

1 Answer

6 votes

Part A

In order to verify if these two lines are parallel, let's rewrite the given equations:

3x - 4y = -2

-4y = -2 - 3x

4y = 2 + 3x

4y = 3x + 2

y = (3/4)x + 2/4

y = 0.75x + 0.5

and

4y = 3x - 12

y = (3/4)x - 12/4

y = 0.75x - 3

As we can see, the slope of both lines is 0.75. So, since they have the same slope, they are parallel lines.

Part B

Now, let's remember that two lines are perpendicular when the slope m2 of one line equals the negative reciprocal of the slope m1 of the other line:

m2 = -1/m1

Now, let's rewrite the given equations, and then compare their slopes:

8x - 2y = 7

-2y = 7 - 8x

2y = 8x - 7

y = (8/2)x - 7/2

y = 4x - 3.5

and

3x + 12y = 9

12y = 9 - 3x

12y = -3x + 9

y = (-3/12)x + 9/12

y = (-1/4)x + 0.75

As we can see, the slope of these lines are:

m1 = 4

m2 = -1/4

Comparing them, we find that:

m2 = -1/4 = -1/m1

m2 = -1/m1

Therefore, these lines are perpendicular.

User Nahydrin
by
7.1k points