X= be coffee
Y=be donuts
Set up equations
10x+5y=16.50
5x+10y=14.25
Now multiply first equation by -2 to get a negative
(-2)10x+5y(-2)=16.50(-2)
-20x-10y=-33
Now put both equations to solve for x
-20x-10y=-33
5x+10y=14.25
___________
-15x. = -18.75
Now divide -15 bith sides to get x alone
X= -18.75/-15
X= 1.25
The cost of each coffee cup$1.25
Let's Simplify X to equal 1 by dividing by 100. then we divide 420 by 100 to get 4.2, so y=4.2 when x=1, we then multiply by each by 11.
y = 46.2
x = 11
The answer is 4^-2 = 1/16