To simplify and solve the equation [tex]\(4m + 9 + 5m - 12 = 42\)[/tex], follow these steps:
1. Combine like terms on the left side of the equation:
[tex]\[
4m + 5m + 9 - 12 = 42
\][/tex]
This simplifies to:
[tex]\[
9m - 3 = 42
\][/tex]
2. Isolate the variable term by adding 3 to both sides of the equation:
[tex]\[
9m - 3 + 3 = 42 + 3
\][/tex]
This further simplifies to:
[tex]\[
9m = 45
\][/tex]
3. Solve for [tex]\(m\)[/tex] by dividing both sides by 9:
[tex]\[
\frac{9m}{9} = \frac{45}{9}
\][/tex]
Simplifying this gives:
[tex]\[
m = 5
\][/tex]
Therefore, the value of [tex]\(m\)[/tex] is [tex]\(\boxed{5}\)[/tex], so the best answer is:
C. [tex]\(m = 5\)[/tex]
