Slope Intercept Form

Slope Intercept Form

Slope Intercept Form

y = mx + b

where m = slope (rate of change) and b = y-intercept (starting point)

Formula for calculating slope:

 $\frac{y_2-y_1}{x_2-x_1}$  where  $\left(x_1,y_1\right)\ and\ \left(x_2,\ y_2\right)$  are points on the line

Horizontal and Vertical Lines

y = a is a horizontal line going through a on the y-axis and with m = 0

x = a is a vertical line passing though a on the x-axis and with an undefined slope.

Multiple Choice

y = 2x - 5

What is the slope of the line?

• 2

• 2x

• -5

• 5

Multiple Choice

y = 2x - 5

Name the y-intercept

• 2

• 2x

• 5

• -5

Multiple Choice

Write an equation with 

 $m\ =\frac{3}{4}$  and  $b\ =\ -1$  

•  $\frac{3}{4}x-\ 1y$  

•  $y\ =\ \frac{3}{4}x+1$  

•  $y\ =\ \frac{3}{4}x-\ 1$  

•  $y\ =\ -x\ +\ \frac{3}{4}$  

Multiple Choice

You have $500 in the bank and plan to deposit $25 every month.

The y-intercept is

• 500

• 25

• -25

• -500

Multiple Choice

You have $500 in the bank and plan to deposit $25 every month.

The slope is

• 500

• 25

• -25

• -500

Open Ended

You have $500 in the bank and plan to deposit $25 every month. Write an equation to model this.

Multiple Choice

How much would you have in the bank after 7 months?

• $3525

• $19.72

• $675

• $325

Poll

You borrow $100 from your parents and agree to pay them back $10 every week.

What does x represent?

• Money still owed

• -10

• weeks

• 100

Poll

You borrow $100 from your parents and agree to pay them back $10 every week.

What does y represent?

• money still owed

• 100

• -10

• weeks

Fill in the Blanks

You borrow $100 from your parents and agree to pay them back $10 every week.

slope =

Fill in the Blanks

You borrow $100 from your parents and agree to pay them back $10 every week.

y-intercept =

Open Ended

You borrow $100 from your parents and agree to pay them back $10 every week.

Write an equation to model this.

Multiple Choice

You borrow $100 from your parents and agree to pay them back $10 every week.

How long until you have repaid your parents completely?

• $100

• 10 weeks

• -10 weeks

• -$100

Multiple Choice

It costs $100 for the electrician to come to your house plus an additional $60 per hour.

x represents

• hours

• per hour

• dollars

• total cost

Fill in the Blanks

It costs $100 for the electrician to come to your house plus an additional $60 per hour.

y represents

Fill in the Blanks

It costs $100 for the electrician to come to your house plus an additional $60 per hour.

slope =

Fill in the Blanks

It costs $100 for the electrician to come to your house plus an additional $60 per hour.

y-intercept =

Open Ended

It costs $100 for the electrician to come to your house plus an additional $60 per hour.

Write an equation to represent the situation

Multiple Choice

How many hours did the electrician work if he charged you $320?

• 1 hour

• 5.3 hours

• 3 hours

• 19300 hours

Multiple Choice

Calculate the slope between (4, -2) and (5, 7)

• $\frac{1}{9}$

• 9

• 5

• $\frac{1}{5}$

Multiple Choice

Find the slope of the line y = 5

• 5

• 0

• undefined

Multiple Choice

Find the slope between the points (1,- 3) and (-3, 8)

• $-\frac{11}{4}$
  

• $\frac{5}{2}$

• $\frac{4}{5}$

• $\frac{2}{5}$