Question 818530
Could you use help but not the actual solution?

Let p = how many pepperoni pizzas,
c = how many of cheese,
s = how many of supreme.


Using the given prices and from the description that {{{p*9=2*s*12}}}, write an equation to account for cost and write an equation to account for the count of the pizzas.  You will have three equations and three unknowns, but you would or could try to eliminate one of them and have a system of two equations in two unknowns; seems more than one way to go.


In any case, simplify that described equation {{{9p=2*12*s}}}, into {{{3p=8s}}}, and then write and use the count and cost equations.



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 A little more:

{{{p+c+s=26}}} and {{{6c+9p+12s=222}}}  which are also based on the problem's descriptions.  A good plan from here would be solve for one of the variables in 3p=8s and substitute the resulting formula into the cost and count equations; and you would have a system of two equations with two unknowns - easier to solve, and probably more comfortable than using matrices.