A pencil costs $0.25 more than an eraser. If the cost of eight pencils is $6.80, what is the cost of one eraser?

The cost of one eraser is $0.6

Step-by-step explanation:

When solving this problem, it's best to set up a system of equations. Let pencil = p and eraser = e.

p = $0.25 + e

8p = $6.80

Now, we can use the second equation to solve for p by dividing both sides by 8. 6.8/8 = 0.85. Therefore, p = $0.85.

Then, use the value of p to find e by plugging the value of p we just found back into the first equation we wrote. Doing so, we get $0.85 = $0.25 + e.   To solve for e, we must subtract 0.25 from both sides, giving use 0.85-0.25 = 0.6

Therefore e = $0.6, so the cost of one eraser is $0.6 or 60 cents.

step-by-step explanation:

you can use a^2+ b^2=c^2