Let p = cost of pens in dollars.
Jane has 20 dollars, she cannot go above this amount, so we should set up an equation.
[tex]15.00+2p=20.00[/tex]
This equation says the fifteen dollar shirt plus the 2 pens she buys has to be equal to $20.00. Let's solve this equation to find the price of the pens. First, we must subtract 15 from both sides. When we do that, we get:
[tex]2p=5.00[/tex]
After that, we must get p by itself, so divide both sides by 2.
[tex]\frac{2p}{2}=\frac{5.00}{2}[/tex]
When we divide and simplify, we get:
[tex]p=\frac{5}{2} [/tex] or [tex] p=2.5[/tex]
The cost of the pens are $2.50. If you want to check your work, plug in 2.50 for p.
[tex]15.00+2(2.5)=20.00[/tex]
[tex]15.00+5=20.00[/tex]
[tex]20.00=20.00[/tex]
This is true. Therefore, the answer is valid.
