Answer:
Cost of one slice of cheese pizza = $1.50
System of equations;
[tex]\begin{gathered} \text{Equation 1: }3x+4y=12.50 \\ \text{Equation 2: }3x+2y=8.50 \end{gathered}[/tex]
Explanation:
Let x represent the cost of one slice of cheese pizza.
Let y represent the cost of one slice of mushroom pizza.
So if Jack bought 3 slices of cheese pizza and 4 slices of mushroom pizza for a total cost of $12.50, we can express this as;
[tex]3x+4y=12.50\ldots\ldots\ldots\text{.Equation 1}[/tex]
And if Grace bought 3 slices of cheese pizza and 2 slices of mushroom pizza for a total cost of $8.50, we can express this as;
[tex]3x+2y=8.50\ldots\ldots\ldots\ldots......\text{Equation 2}[/tex]
We can now solve both equations simultaneously using the elimination method.
Subtracting equation 2 from equation 1, we'll have;
[tex]\begin{gathered} 2y=4 \\ y=\frac{4}{2} \\ y=2 \end{gathered}[/tex]
To find x, let's put y = 2 into Equation 1 and solve for x;
[tex]\begin{gathered} 3x+4(2)=12.5 \\ 3x=4.5 \\ x=\frac{4.5}{3} \\ x=1.5 \end{gathered}[/tex]
We can see that the cost of one slice of cheese pizza is $1.50.