Question

Simplify and solve this equation: 4m + 9 + 5m – 12 = 42.
Question 18 options:

A)

m = –5

B)

m = -4

C)

m = 4

D)

m = 5

Answer 1

To simplify and solve the equation \( 4m + 9 + 5m - 12 = 42 \), we can follow these steps:

1. Combine like terms on the left side:
\[
4m + 5m + 9 - 12 = 42
\]
This simplifies to:
\[
9m - 3 = 42
\]

2. Next, add 3 to both sides to isolate terms involving \( m \):
\[
9m - 3 + 3 = 42 + 3
\]
This gives us:
\[
9m = 45
\]

3. Now, divide both sides by 9 to solve for \( m \):
\[
m = \frac{45}{9} = 5
\]

Thus, the solution is:
\[
m = 5
\]

The correct answer is **D) m = 5**.