Let brownies=x, cookies=y
First equation
[tex]11 = 3x + 5y[/tex]
Second equation
[tex]3.95 = x + 2y[/tex]
Rearrange second equation
[tex]3.95 - x = 2y[/tex]
[tex]y = \frac{3.95 - x}{2} [/tex]
Substitude y into first equation
[tex]11 = 3x + 5( \frac{3.95 - x}{2} )[/tex]
Solve x
[tex]11 = 3x + ( \frac{19.75 - 5x}{2} )[/tex]
[tex]11 = 3x + 9.875 - \frac{5}{2} x[/tex]
[tex]11 - 9.875 = \frac{1}{2} x[/tex]
[tex]1.125 = (0.5)x[/tex]
[tex]x = \frac{1.125}{0.5} [/tex]
[tex]x = 2.25[/tex]
Thus, the price of a brownie is $2.25.
