1. Simplify the monomial: $-7a + 43a$ 2. First, state the problem: Combine like terms $-7a$ and $43a$. 3. Use the rule for adding like terms: $ka + ma = (k+m)a$ where $k$ and $m$ are constants. 4. Calculate the sum of coefficients: $-7 + 43 = 36$. 5. Write the simplified expression: $$-7a + 43a = 36a$$ Final answer: $36a$