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3 years ago

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?

Mathematics

2 answers:

Llana [10]3 years ago

8 0

Answer:

A single pencil costs $0.85 and a single eraser costs $0.60

lora16 [44]3 years ago

5 0

Answer: 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.

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Note we multiplied by x and did not flip the inequality sign because its value cannot be negative.

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The expression is given as:

$(x + 4)^5$

To expand the expression, we make use of Pascal triangle, where:

5:= 1 5 10 10 5 1

So, we have:

$(x + 4)^5 = 1 * x^5 * 4^0 + 5 * x^4 * 4^1 + 10 * x^3 * 4^2 + 10 * x^2 * 4^3 + 5 * x * 4^4 + 1 * x^0 * 4^5$

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Read more about binomial expressions at:

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2 years ago

Read 2 more answers