The cost of one hamburger is $2
Here, we want to get the cost of one hamburger
Let the cost of the hamburger be h and the cost of the soda be s
[tex]\begin{gathered} 3h\text{ + 2s = 7.5} \\ \text{but s = \$0.75} \\ 3h\text{ + 2(0.75) = 7.5} \\ 3h\text{ + 1.5 = 7.5} \\ 3h\text{ = 7.5-1.5} \\ 3h\text{ = 6} \\ h\text{ = }\frac{6}{3} \\ h\text{ = \$2} \end{gathered}[/tex]