Simplify and solve this equation 4m + 9 + 5m - 12=42

m = 5

Explaination:

Given equation is:

4m + 9 + 5m - 12=42

We need to solve this, We see that given equation is linear equation

So, we simplify the left hand side

4m + 9 + 5m - 12=42

Combine like terms

here 4m & 5m are like terms

4m + 5m + 9-12 = 42

9m + 9 - 12 = 42

9m + - 3 = 42

Now move - 3 to right side

9m = 42 + 3

9m = 45

m = 5