ANSWER
16
EXPLANATION
The given expression is;
[tex]3 {x}^{2} + 4 {y}^{2} [/tex]
If x=2, y=1 and z=-3, we substitute the values into the expression and solve.
We substitute to obtain;
[tex]3 {(2)}^{2} + 4 {(1)}^{2} [/tex]
We evaluate to get;
[tex]3 {(4)} + 4 {(1)}[/tex]
We multiply out to get:
[tex]12+ 4 = 16[/tex]
Therefore the value of the given expression is with the given values is 16
