[tex]\implies {\blue {\boxed {\boxed {\purple {\sf {21}}}}}}[/tex]
[tex]\large\mathfrak{{\pmb{\underline{\orange{Step-by-step\:explanation}}{\orange{:}}}}}[/tex]
[tex]3 \: ( \: x + 2 \: )[/tex]
Plugging in the value [tex]x = 5[/tex] in the above expression, we have
[tex] = 3\:( \: 5 + 2 \: )[/tex]
[tex] = 3 \: ( \: 7 \: )[/tex]
[tex] = 3 \times 7[/tex]
[tex] = 21[/tex]
[tex]\sf\pink{PEMDAS\: rule.}[/tex]
P = Parentheses
E = Exponents
M = Multiplication
D = Division
A = Addition
S = Subtraction
[tex]\red{\large\qquad \qquad \underline{ \pmb{{ \mathbb{ \maltese \: \: Mystique35☂}}}}}[/tex]