Slope-Intercept Form: Practice Problems with Solutions

Problem 1: Find the equation of a line with a slope of 3 and a y-intercept of -2.

Solution:

Using the slope-intercept form y=mx + b

Putting the value of m = 3, b = -2;

y = 3x – 2

Problem 2: Determine the slope-intercept form of the line passing through the points (2, 4) and (4, 8).

Solution:

First, find the slope y – y₁ = m(x – x₁)

m = (y – y₁) / (x – x₁)

m = (8 -4) / (4 – 2) ⇒ 4 / 2 ⇒ 2

Next, use one of the points, say (2, 4), and the slope to find b:

4 = 2(2) + b

⇒ b = 0

Required equation is: y = 2x

Problem 3: Convert the equation 2x – 3y = 6 to slope-intercept form.

Solution:

Solve for y:

– 3y = – 2x+6

y = 2x / 3 – 2

This is the required equation in slope intercept form.

Problem 4: What is the y-intercept of the line y = – 5x + 7?

Solution:

Given Equation,

y = – 5x + 7

comparing with, y = mx + c

The y-intercept is c = 7

Problem 5: Find the slope and y-intercept of the line given by the equation y = x/2 – 4.

Solution:

Given Equation,

y = x/2 – 4

comparing with, y = mx + c

Slope (m) = 1/ 2

​y-intercept (c) = – 4

Problem 6: Find the slope and y-intercept of the line passing through (1, 5) and (3, 9).

Solution:

Given points,

• (x₁, y₁) = (1, 5)
• (x₂, y₂) = (3, 9)

Slope of line(m) = (y₂ – y₁)/(x₂ – x₁)

m = (9 – 5) / (3 – 1) = 2

⇒ m = 2

Equation of line with slope(m = 2) and passing through (1, 5)

y – 5 = 2(x – 1)

y = 2x + 3

Slope m = 2, y-intercept (c) = 3

Problem 7: Determine the equation of the line with slope -4 that passes through the point (2, -1).

Solution:

Given points,

• (x₁, y₁) = (2, -1)
• m = -4

Using the point-slope form: y – y₁ = m(x – x₁)

y + 1 = – 4(x – 2)

Convert to slope-intercept form: y = – 4x + 7

Problem 8: If the line y = 5x + b passes through the point (1, 2), find b.

Solution:

Putting the values of (1,2) in the given equations

2 = 5(1) + b

2 = 5 + b

b = – 3

Problem 9: Find the equation of a horizontal and vertical line passing through (4, -2)

Solution:

• A horizontal line has a slope of ‘0’

Horizontal passing through (4, -2)

y = – 2

• A vertical line has an undefined slope

Vertical line passing through (4, -2)

x = 4

Read more,

• Point-slope Form
• X and Y Intercept
• Equation of Straight Line

Slope-intercept form plays a very important role as it is needed for solving linear equations. It is such a key element because this is a simple and also quite practical way to graph and interpret linear quadratic functions. The main goal of the report is to explain the slope-intercept form as a dominant and widely used linear algebra concept as well as offer a detailed solution to the questions related to this subject.