Final answer:
To distribute and combine like terms for the expression 9a + 10(6a - 1), you distribute the 10 into the parentheses, perform the multiplication, combine like terms, and then simplify to get the result 69a - 10.
Step-by-step explanation:
To distribute and combine like terms in the expression 9a + 10(6a - 1), first distribute the 10 to both terms inside the parentheses:
9a + 10 * 6a - 10 * 1
Next, perform the multiplications:
9a + 60a - 10
Now, combine the like terms, which are the terms with 'a':
(9a + 60a) - 10
Add the coefficients of 'a':
69a - 10
Thus, the distributed and simplified expression is 69a - 10. Always remember to eliminate terms wherever possible to simplify the algebra and check that the answer is reasonable.