Math Problem Statement

Write an equation of a line in slope intercept form that passes through the points (5,5) and (4,-2). If needed leave slope and y-intercept as an improper fraction and no spaces in your answer. Make sure your answer is an equation.

Solution

To find the equation of a line in slope-intercept form, we need to use the formula:

y=mx+by = mx + b

where mm is the slope and bb is the y-intercept.

Step 1: Find the slope mm

The slope formula between two points (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is:

m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}

Substituting the given points (5,5)(5, 5) and (4,2)(4, -2):

m=2545=71=7m = \frac{-2 - 5}{4 - 5} = \frac{-7}{-1} = 7

Step 2: Use the slope-intercept form

Now that we have the slope m=7m = 7, substitute one of the points (we’ll use (5,5)(5, 5)) and the slope into the equation y=mx+by = mx + b to find the y-intercept bb.

5=7(5)+b5 = 7(5) + b

5=35+b5 = 35 + b

b=535=30b = 5 - 35 = -30

Step 3: Write the equation

Now that we have both the slope m=7m = 7 and the y-intercept b=30b = -30, the equation of the line is:

y=7x30y = 7x - 30

This is the equation of the line in slope-intercept form.

Would you like further details or explanations?


Here are 5 related questions:

  1. What is the slope of a line that passes through the points (1, 2) and (3, 8)?
  2. How do you convert the equation 2x3y=62x - 3y = 6 into slope-intercept form?
  3. What is the significance of the slope in a linear equation?
  4. Can a vertical line be written in slope-intercept form?
  5. How do you find the y-intercept if you only know the slope and one point?

Tip: To quickly find the slope between two points, remember it’s just the "rise over run" or the change in yy values divided by the change in xx values.

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Math Problem Analysis

Mathematical Concepts

Algebra
Linear Equations
Slope-Intercept Form

Formulas

Slope formula: m = (y2 - y1) / (x2 - x1)
Slope-intercept form: y = mx + b

Theorems

Line through two points theorem

Suitable Grade Level

Grades 8-10