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

Question

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.