Joe buys 5 pencils for W dollars. Write an algebraic equation for how many pencils Joe can buy with $20

Answer 1

Let's break this down:

W is the cost of 5 pencils. Since we're solving for the number of pencils Joe can buy, we'll need to give it a variable. Let's call the number of pencils x.

So, if Joe buys 5 pencils for W dollars, where the cost of one pencil is P dollars: 5P=W

Now we can simplify that equation so it can tell us the cost of a single pencil: P=(W/5)

The equation that represents the number of pencils that can be bought for $20 in words would be: 20 dollars (total cost) equals the cost of one pencil times the number of pencils bought. This can be represented as:

$20=(cost of a pencil)*(number of pencils)

Using our variables:

$20=P*x

Lastly, we want to give an answer using the variable (W) given to us, so we use our expression that tells us what P equals in terms of W:

$20=(W/5)*x