Examples with solutions for Linear Function y=mx+b: Using slope for geometric problems

Exercise #1

In the drawing of the graph of the linear function passing through the points A(0,7) A(0,7) and
B(8,3) B(8,-3)

Find the slope of the graph.

A(0,7)A(0,7)A(0,7)B(8,-3)B(8,-3)B(8,-3)CCCxy

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the coordinates of the points.

  • Step 2: Apply the slope formula.

  • Step 3: Perform the arithmetic to calculate the slope.

Let's work through each step:

Step 1: Identify the given points:
Point A A is (0,7) (0, 7) and Point B B is (8,3) (8, -3) .

Step 2: Use the slope formula, which is: m=y2y1x2x1 m = \frac{y_2 - y_1}{x_2 - x_1}

Substituting the coordinates of points A A and B B :
Here, (x1,y1)=(0,7) (x_1, y_1) = (0, 7) and (x2,y2)=(8,3) (x_2, y_2) = (8, -3) .

Step 3: Calculate the slope:
m=3780=108=54 m = \frac{-3 - 7}{8 - 0} \\ = \frac{-10}{8} \\ = -\frac{5}{4}

Therefore, the slope of the graph is 54 -\frac{5}{4} .

Answer

54 -\frac{5}{4}

Exercise #2

In the drawing of the graph of the linear function passing through the points A(2,10) A(2,10) y B(5,4) B(-5,-4)

Find the slope of the graph.

A(2,10)A(2,10)A(2,10)CCCB(-5,-4)B(-5,-4)B(-5,-4)xy

Video Solution

Step-by-Step Solution

To find the slope of the graph of the linear function passing through points A(2,10) A(2,10) and B(5,4) B(-5,-4) , we use the slope formula:

The slope formula is given by:

m=y2y1x2x1 m = \frac{y_2 - y_1}{x_2 - x_1}

Substitute (x1,y1)=(2,10) (x_1, y_1) = (2, 10) and (x2,y2)=(5,4) (x_2, y_2) = (-5, -4) :

m=41052 m = \frac{-4 - 10}{-5 - 2}

Calculate the differences:

y2y1=410=14 y_2 - y_1 = -4 - 10 = -14

x2x1=52=7 x_2 - x_1 = -5 - 2 = -7

Substitute these into the slope formula:

m=147 m = \frac{-14}{-7}

Simplify:

m=147=2 m = \frac{-14}{-7} = 2

Therefore, the slope of the graph is 2 2 .

Answer

2 2

Exercise #3

In the drawing of the graph of the linear function passing through the points A(3,2) A(-3,2) y B(3,2) B(3,2)

Find the slope of the graph.

A(-3,2)A(-3,2)A(-3,2)B(3,2)B(3,2)B(3,2)CCCDDDxy

Video Solution

Step-by-Step Solution

To determine the slope of the line passing through points A(3,2) A(-3, 2) and B(3,2) B(3, 2) , we will use the slope formula:

The slope m m is calculated as:

m=y2y1x2x1 m = \frac{y_2 - y_1}{x_2 - x_1}

Substituting the values from points A(3,2) A(-3, 2) and B(3,2) B(3, 2) , we get:

m=223(3)=06=0 m = \frac{2 - 2}{3 - (-3)} = \frac{0}{6} = 0

The calculation shows that the difference in y y -coordinates is zero, hence dividing by any non-zero number will result in a slope of zero. This indicates a horizontal line on the graph.

Therefore, the slope of the line is 0 0 .

Answer

0

Exercise #4

In the drawing of the graph of the linear function passing through the points A(0,10) A(0,-10) y B(4,1) B(4,1)

Find the slope of the graph.

A(0,-10)A(0,-10)A(0,-10)CCCB(4,1)B(4,1)B(4,1)xy

Video Solution

Step-by-Step Solution

To solve this problem, we need to calculate the slope of the line passing through the points A(0,10) A(0, -10) and B(4,1) B(4, 1) .

The formula for the slope m m of a line that passes through two points (x1,y1) (x_1, y_1) and (x2,y2) (x_2, y_2) is:

m=y2y1x2x1 m = \frac{y_2 - y_1}{x_2 - x_1}

Given the points A(0,10) A(0, -10) and B(4,1) B(4, 1) , we identify:

  • x1=0,y1=10 x_1 = 0, y_1 = -10
  • x2=4,y2=1 x_2 = 4, y_2 = 1

Substituting these values into the slope formula, we have:

m=1(10)40 m = \frac{1 - (-10)}{4 - 0}

This simplifies to:

m=1+104=114 m = \frac{1 + 10}{4} = \frac{11}{4}

The fraction 114\frac{11}{4} can be converted to a mixed number:

114=234 \frac{11}{4} = 2\frac{3}{4}

Therefore, the slope of the graph is 234 \bm{2\frac{3}{4}} .

Answer

234 2\frac{3}{4}

Exercise #5

In the drawing of the graph of the linear function passing through the points A(0,7) A(0,7) y B(4,9) B(-4,-9)

Find the slope of the graph.

A(0,7)A(0,7)A(0,7)CCCxyB(-4, -9)

Video Solution

Step-by-Step Solution

To find the slope (m m ) of the line passing through the points A(0,7) A(0,7) and B(4,9) B(-4,-9) , we apply the slope formula:

m=y2y1x2x1 m = \frac{y_2 - y_1}{x_2 - x_1}

First, assign the coordinates to the two points:

  • (x1,y1)=(0,7)(x_1, y_1) = (0, 7)
  • (x2,y2)=(4,9)(x_2, y_2) = (-4, -9)

Next, substitute these into the slope formula:

m=9740 m = \frac{-9 - 7}{-4 - 0}

Simplify the expression:

m=164 m = \frac{-16}{-4}

The negative signs in the numerator and denominator cancel out:

m=164 m = \frac{16}{4}

Finally, divide to find the slope:

m=4 m = 4

Therefore, the slope of the line passing through points A(0,7) A(0,7) and B(4,9) B(-4,-9) is 4 4 .

Answer

4 4

Exercise #6

In the drawing of the graph of the linear function passing through the points A(1,7) A(1,7) y D(8,2) D(8,2)

Find the slope of the graph.

A(1,7)A(1,7)A(1,7)CCCD(8,2)D(8,2)D(8,2)BBBxy

Video Solution

Step-by-Step Solution

To find the slope of the linear function passing through the points A(1,7) A(1,7) and D(8,2) D(8,2) , we will use the formula for the slope between two points:

m=y2y1x2x1 m = \frac{y_2 - y_1}{x_2 - x_1}

Let us assign the coordinates (x1,y1)=(1,7) (x_1, y_1) = (1, 7) and (x2,y2)=(8,2) (x_2, y_2) = (8, 2) .

Substitute these values into the slope formula:

m=2781 m = \frac{2 - 7}{8 - 1}

Calculate the differences in the numerator and the denominator:

m=57 m = \frac{-5}{7}

Therefore, the slope of the line passing through points A(1,7) A(1,7) and D(8,2) D(8,2) is 57-\frac{5}{7}.

In conclusion, the correct answer is 57-\frac{5}{7}.

Answer

57 -\frac{5}{7}

Exercise #7

Find the slope of the line I I

III(2,5)(10,1)XY

Video Solution

Answer

m=2 m=2

Exercise #8

ABCD is a square.

Calculate the slope of line AD.

A(0,10)A(0,10)A(0,10)BBBCCCDDD(-2,5)

Video Solution

Answer

m=212 m=2\frac{1}{2}

Exercise #9

ABCD is a Square.

Calculate the slope of line AB.

A(0,10)A(0,10)A(0,10)BBBCCCDDD(-2,5)

Video Solution

Answer

m=25 m=-\frac{2}{5}

Exercise #10

ABCD is a square.

Calculate the slope of the line DC.

A(0,10)A(0,10)A(0,10)BBBCCCDDD(-2,5)

Video Solution

Answer

m=25 m=-\frac{2}{5}

Exercise #11

ABCD is a square.

Calculate the slope of the line BC.

A(0,10)A(0,10)A(0,10)BBBCCCDDD(-2,5)

Video Solution

Answer

m=212 m=2\frac{1}{2}