Question

Find the slope of a line perpendicular to the line defined by the equation 3x-5y=12

Answer 1

5

m = - ---- perpendicular slope

3

Explanation:

3x - 5y = 12 -------->> convert to y = mx + b

- 5y = - 3x + 12

- 5y = - (3x + 12) --- eliminate the negative

5y = 3x + 12

3x + 12

y = -------------

5

3 12

y = -----x + -----

5 5

the above equation is the form of y = mx + b

where m is the slope and b is the intercept

5

therefore, m = - ---- perpendicular slope

3

Answer 2

-5/3

Explanation:

Note the slope intercept form: y = mx + b

Note that:

y = (x , y)

m = slope

x = (x , y)

b = y-intercept

Isolate the variable, y. First, Subtract 3x from both sides:

3x (-3x) - 5y = 12 (-3x)

-5y = -3x + 12

Next, divide -5 from both sides. Remember to divide from all terms within the equation:

(-5y)/-5 = (-3x + 12)/-5

y = (-3x/-5) + (-12/5)

Simplify.

y = (3x/5) - 12/5

y = (3/5)x - 12/5

You are trying to find the perpendicular slope to this line. To do so, simply flip the slope (m) as well as the sign:

Original m = 3/5

Flipped m = -5/3

-5/3 is your perpendicular slope.