1. Let

be the number of small balloons and

the number of large balloons. We know that cost of a small balloon is $3, so the cost of

small balloons is

; similarly, we know that the cost of a large balloon is $5, so the cost of

small balloons is

. Now to find the total cost

of

small balloons and

large balloons, we just need to add their individual cost together:

We can conclude that an algebraic expression for the cost of x small balloons and y large balloons is
2. To find the the total cost for 11 small balloons and 6 large balloons, we just need to replace

with 11 and

with 6 in our algebraic expression and simplify:




We can conclude that the total cost of 11 small balloons and 6 large balloons is $63