A baker has 130 cookies to decorate for a charity event. He can decorate 10 cookies per hour.

Question

Which equation represents the number of cookies, y, that the baker still needs to decorate after x hours?

Answer options with 4 options
A.
y equals 10 x minus 130

B.
y equals 10 x plus 130

C.
y equals negative 10 x minus 130

D.
y equals negative 10 x plus 130

Answer 1

To find the equation that represents the number of cookies, $y$, that the baker still needs to decorate after $x$ hours, we start with the initial amount of cookies and take into account the number of cookies decorated over time.

Initially, the baker has 130 cookies to decorate. If he decorates 10 cookies per hour, after $x$ hours, he will have decorated $10x$ cookies.

To find out how many cookies he still needs to decorate, we can start with the initial amount and subtract the amount decorated:

$$y=130-10x$$

This represents the remaining cookies, $y$, after $x$ hours. We can rearrange the equation to show it in a different form:

$$y=-10x+130$$

From the options provided, this matches option D:

D. $y=-10x+130$

Thus, the correct answer is D.