Question

Betty's grade in science class is affected by the number of missing assignments. The table below shows the science grade percentage for a given number of missing assignments.

Number of missing assignments: 3,5,7,9
Science grade%: 80,70,60,50
The equation for the given table is y=-5x+95. If Betty is missing 15 assignments, what's the [percentage of her grade in science class?

What is the rate of change?

Answer 1

Hi!

`y=-5x+95`

Plug in
`15` for
`x`

`y=-5(15)+95`

Multiply
`-5` and
`15`

`y=-75+95`

Add
`-75` and
`95`

`y =15`

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Betty's percentage is 15%.

The rate of change is the amount it changes for every missing assignment, therefore it would be -5.