Question

Find the equation of a line with each of the following characteristics. A) Parallel to the line y = 3x + 5 and has a y-intercept of -1 B) Perpendicular to the line y = 5x - 1 and passes through the point (10, 8) C) Perpendicular to the line y = 1⁄3x + 4 and has an x-intercept of 2.

Answer 1

A) y = 3x - 1.

B) y = -1/5x + 10.

C) y = -3x + 6.

Explanation:

A) It is parallel, so it will have the same slope of 3. The y-intercept is -1.

So, we have y = 3x - 1.

B) It is perpendicular, so it will have the negative reciprocal slope of -1/5.

To find the y-intercept, put the points into the equation.

8 = -1/5(10) + b

8 = -2 + b

b - 2 = 8

b = 10

So, we have y = -1/5x + 10.

C) It is perpendicular, so the slope will have a negative reciprocal of -3. The x-intercept is 2, so it has a point at (2, 0). We put that into the equation.

0 = -3 * 2 + b

0 = -6 + b

b - 6 = 0

b = 6

So, we have y = -3x + 6.

Hope this helps!

Answer 2

Equation of a line is y = mx + c

where m is the slope

c is the y intercept

A).

y = 3x + 5

Comparing with the above formula

Slope / m = 3

y intercept = - 1

Since the lines are parallel their slope are also the same

Substituting the values into the formula

We have the final answer as

y = 3x - 1

B).

y = 5x - 1

Slope / m = 5

Since the lines are perpendicular the slope of the line is the negative inverse of the original line

That's

m = - 1/5

Equation of the line using point (10, 8) is

y - 8 = -1/5( x - 10)

y - 8 = -1/5x + 2

The final answer is

y = -1/5x + 10

C).

y = ⅓x + 4

Slope / m = ⅓

Since the lines are perpendicular the slope of the line is the negative inverse of the original line

That's

m = - 3

Equation of the line using point (2,0) is

y - 0 = -3( x - 2)

We have the final answer as

y = - 3x + 6

Hope this helps you