Question

Jade is going shopping. She wants to buy a jacket for $25 and a few shirts that cost $11 each. She wants to spend less than $80.

Answer 1

Let J be the jacket and S the shirts. Jade wants to know how many shirts she can buy.

Then, we can write the following relationship:

$25\cdot J+11\cdot S=80$

since Jade only wants one jacket, this means that J=1. Then, by substituting these value into our formula, we have

$25\cdot1+11\cdot S=80$

which gives

$25+11S=80$

Now, if we move 25 to the right hand side as -25, we obtain

$\begin{gathered} 11S=80-25 \\ 11S=55 \end{gathered}$

and finally, we have

$\begin{gathered} S=\frac{55}{11} \\ S=5 \end{gathered}$

that is, Jade can buy 5 shirts and 1 jacket with $80.