Answer:
[tex]81[/tex]
Step-by-step explanation:
The initial expression:
[tex]x^2+3yz[/tex]
Identify your values:
[tex]x=3\\y=6\\z=4[/tex]
Substitute:
[tex](3)^2+3(6)(4)[/tex]
Following PEMDAS, nearly everything is in parentheses, so move to exponents:
[tex]9+3(6)(4)[/tex]
Multiply [tex]6[/tex] and [tex]4[/tex]:
[tex]9+3(24)[/tex]
Multiply [tex]3[/tex] and [tex]24[/tex]:
[tex]9+72[/tex]
Simplify:
[tex]81[/tex]