Thursday Warm Up

Thursday Warm Up. Summer Jobs! You have 2 summer jobs. You work 20 hours per week at the first job and earn $7.75 per hour. You make $6.75 per hour at the 2nd job. How many hours will you have to work at the 2nd job if you want to make a total of $250 per

week with both jobs together? Write an equation and solve.

The bill to fix your home air conditioner was $824.14. The parts cost $425.14 and the service technician charged $55.00 per hour in labor costs. Write an equation

and solve for how many hours the mechanic takes to fix your car?

. 25(7.75) + 6.25x = 250 x = 9 hours

425.14 + 45x = 824.14 x = 8.87 hours

Objective

• I can graph linear equations.

Vocabulary

• X intercept• Y intercept• Slope• Slope intercept form• Standard form

X interceptAn x-intercept is a point in the equation where the y-value is zero

Where the graph intersects the x axis

Also referred to as “root”, “solution”, “zeroes”

Y interceptA y-intercept is a point in the equation where the x-value is zero.

Where the graph intersects the y axis

Represented with the letter “b”

Slope

How steep or flat a line is

Rise/Run Represented by “m”

Why the letter m??? Nobody knows!

Slope Intercept Form

Slope of the line

Y intercept or where the graph crosses the y axis (remember b for where to begin the graph)

Y = mx + b

m represents?

b represents?

Practice• Complete table and graph

y = (-3/4)x + 3

x intercept ( , )y intercept ( , )

y = -(2/5)x – 2

x intercept ( , )y intercept ( , )

x -2 -1 0 1 2

y

x -2 -1 0 1 2

y

Standard Form

2x + 5y = 10X intercept (5, 0)

Y intercept (0, 2)

Ax + By = C

Can graph using x and y intercepts

Use cover up method to find intercepts

Graph using standard form

• 2x + 6y = 12

• X intercept ( , )• Y intercept ( , )

x -2 -1 0 1 2y

Convert to Slope-Intercept Form

• Find the slope and y intercept, then graph -2x + 3y = 9

3y = 2x + 9 (Add 2x to both sides)Y = (2/3)x + 3 (Divide both sides by 3)

Slope = 2/3

Y intercept 3

.

Practice