Writing Linear Equations and Slope Review

What is the equation for this table?

• y=2x+5

• y=2x+3

• y=-2x+5

• y=-2x+3

Answer explanation

When you see a TABLE, enter it in lists and spreadsheets on the calculator and use MENU 413 to find m and b.

Find the slope.

• 9/5
• 5/9
• -9/5
• -5/9

Answer explanation

This equation is in STANDARD FORM, Ax+By=C.

To find the slope, divide A by -B.

Daniel went to a fruit market where he found that oranges cost $4 per pound and bananas cost $2 per pound. He bought some oranges and bananas and the total cost was $28.

If "x" represents the pounds of oranges Daniel bought and "y" represents the pounds of bananas, which equation models this situation?

• 2x + 4y = 28

• 4x + 2y = 28

Answer explanation

Ax+By=C

A and B represent the cost of the items.

C represents the total cost. You just have to make sure you get the variables matched to their correct costs.

What is the equation of the line?

Answer explanation

y=mx+b from a graph.

To find the slope(m), find rise/run. Make sure if the graph is going down, you put that the slope is NEGATIVE. The y-intercept is where the line crosses the vertical y-axis.

You could also identify the two points on the graph and enter them in lists and spreadsheets (Menu 413).

Find the slope of the line that passes through:
(-2, 8) and (0, 8)

• 0
• -2
• 2
• 1/2

Answer explanation

Two points can be put in lists and spreadsheets as a table. MAKE SURE YOU READ THE QUESTION! You are only looking for slope (m).

• 5
• -5

Answer explanation

slope is the number in front of x and the y-intercept is the number on the end of the equation. LOOK OUT FOR NEGATIVES! Double check your answers to make sure you put a negative in your answer if it needs one.

Write a linear equation in the form of y=mx+b

• y = 2x + 2

• y = 2x - 2

• y = x + 2

• y = 3x - 2

Answer explanation

To write an equation from a table, use lists and spreadsheets app. Find m and b. Write your equation y=mx+b.

Mathematical Equivalence

ON

Answer explanation

Make sure you write the whole equation. y=mx+b.

M is the slope, rise/run. B is where the line crosses the vertical y-axis. Double check that you typed it correct with the equal sign.

You can also find two points and do list and spreadsheet if that is easier for you.

Ryan's Auto Wash earns revenues of $9 per customer. What is the rate of change?

Answer explanation

Keywords to look for when determining rate of change (which is the same thing as slope!) are...

PER and EACH.

Determine the Constant Rate of Change?

• -10 ft per second
• 15 ft per second
• 10 ft per second 
• -15 ft per second

Answer explanation

If the graph is going down the rate of change/slope is negative. Don't forget!