SOLUTION: show that the following lines are perpendicular : y= 2x + 2 & 4y + 3 = -2x

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Question 314821: show that the following lines are perpendicular : y= 2x + 2 & 4y + 3 = -2x
Found 2 solutions by texttutoring, unlockmath:
Answer by texttutoring(324) About Me  (Show Source):
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perpendicular lines have slopes that are negative reciprocals of each other.

Recall the equation of a line, y=mx+b, where m=slope

The first line, y=2x+2, has a slope of 2.

Rearrange the second equation so that it is in y=mx+b form:
4y+3=-2x
4y=-2x-3
y=-2x/4 -3/4

So the slope of the second line is -2/4 or -1/2 in simplest terms.

The negative reciprocal of -1/2 is 2/1

slope of line 1 = 2
slope of line 2 = -1/2

The lines are perpendicular because their slopes are negative reciprocals of each other.

Answer by unlockmath(1688) About Me  (Show Source):
You can put this solution on YOUR website!
Hello,
Let's first get these y= 2x + 2 & 4y + 3 = -2x in standard form as:
y= 2x + 2
y= -1/2x-3/4
We know that in y=mx+b that m is the slope of the line. The perpendicular to m is -1/m
Thus it proves out that these are perpendicular to each other.
Make sense?
RJ
www.math-unlock.com