To solve a problem where we already know the value of the variables, we should simply substitute in the value of the variable for every instance of the variable, and then solve like a normal math problem.
[tex] 3x^{2} - y^{3} - y^{3} - z \\ 3*3^{2} - ⁻2^{3} - ⁻2^{3} - ⁻5 \\ 3*9 - ⁻8 - ⁻8 - ⁻5 \\ 27 - 5 \\ 22 [/tex]
Using the math above, we can see that the value of this expression is 22.
