Practice LE A1b

the table shows the relationship between x and y. What is the increase in the value of y as the value of x increases by 1?

• 3

• 4

• 6

• 9

Answer explanation

Remember the slope is also the increase in value of y divided by the increase in value of x.

Which of the following situations is NOT best represented by a linear equation?

• the height of a ball as it is thrown up and falls to the ground

• the total distance run around a track as a function of the number of laps

• the distance travelled by a train as a function of time

• the price of a piece of fabric as a function of the length

Answer explanation

A linear function will have a constant slope (rate of change). If the numbers go up or down very fast, or don't always go in the same direction (+ or -), then it can't be a linear function.

For a linear function, as the x values change, the y values change at a...

• constant rate

• constant percentage

• undefined rate

• variable rate

Answer explanation

Linear functions make a straight line, with a constant rate of change.

Consider the graph. What is the slope of the line?

(Use only numbers, a negative (-), decimals (.), or forward slashes (/) for your answer).

(a)  

Answer explanation

Slope from a graph is rise/run, or the change in y over the change in x.

Which table shows an account that increases at a constant amount each month?

• A

• B

• C

• D

Answer explanation

See how much the values go up each time. Is it the same every time, or does it change? It has to be exactly the same for a linear function.

Which statement best describes the data in the table?

• the value of y is 4 more than the value of x

• the value of y is 4 less than the value of x

• the value of y is twice the value of x

• the value of y is four times the value of x

Answer explanation

This is the same as "find the rule". Is y a multiple of x? Is y always the same amount less than x, or the same amount more than x? If the negative numbers confuse you, work with either the line with a 0 in it, or just a positive row.