Alex is ordering his girlfriend a bouquet of flowers for their anniversary.roses cost $5 each and carnations cost $2 each. He would like to include at least 3 flowers. To stay on budget he must not spend more than $36.

The equations of the function is

Y=2x+ 5y
Y<(less than or equal to) 36
X+y>( greater than or equal to) 3

So to find one variable in the equation such as finding the amount of roses or carnations, you would have to do system of equations. Some ways of using system of equations is to use substitution, elimination, or graphing.