[tex]\text{Solve by plugging 4 to m:}\\\\(4)^2+3(4)\\\\16+3(4)\\\\16+12\\\\28\\\\\boxed{\text{D). 28}}[/tex]
The value of the expression [tex]m^{2} + 3m[/tex] when m =4 is 21.
An expression is a combination of numbers, variables, functions such as addition, subtraction, multiplication or division etc.
The process of swapping an algebraic letter for its value is called substitution.
According to the given question we have
An expression
[tex]m^{2} +3m[/tex]
We have to find the value of given expression when m =4, for this substitute the m =4 in the expression [tex]m^{2} + 3m[/tex]
⇒ [tex](3)^{2} + 3(4)[/tex]
⇒ 9 + 12 = 21
Hence, the value of [tex]m^{2} + 3m[/tex] when m =4 is 21.
Learn more about the expression and substitution here:
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