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OGRAPHS AND FUNCTIONSFinding slopes of lines parallel and perpendicular to a line given.

OGRAPHS AND FUNCTIONSFinding slopes of lines parallel and perpendicular to a line-example-1
User Liorda
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1 Answer

3 votes

We have the next line:


-5x\text{ - 7y = -8}

Solve the equation using the slope-intercept form:


y\text{ = mx + b}

Where m is the slope and b is the y-intercept:

Solving the equation:

-5x - y7 = -8

Add 5x on both sides

-5x + 5x - y7 = -8 + 5x

-7y = -8 +5x

Divide by 7 into both sides:

-7y/7 = (-8 +5x)/7

-y = (-8 +5x)/7

Multiply by -1 to calcel the negative sign:

(-1)(-y) =(-1)* (-8 +5x)/7

y = (8 -5x)/7

y = -5x/7 + 8/7

Now, we need to find the slope of a line perendicular to this line.

"Two lines are perpendicular if and only if their slopes are negative" reciprocals"

So the slope, in this case, is -5x/7

To find the perpendicular line use:

-5x/7 * m = -1

Solve the equation m:

m = (-1)/(-5x/7)

m = 7/5x

So m = 7/5x is the slope of the perpendicular line.

To find the parallel line use:

"Two lines are parallel lines if they do not intersect. The slopes of the"

lines are the same."

So m = -5x/7

User Jkigel
by
4.6k points
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