7a + 6c + 9a - 15c
-- Look for all the 'a's 7a, 9a
-- Addum up 16a
-- Look for all the 'c's 6c, -15c
-- Addum up -9c
-- Write the results 16a - 9c
<h3>
Answer: Choice C</h3>
Work Shown:

So that's why the answer is choice C
The requirement that x is nonzero isn't technically necessary. The original expression simplifies to choice C even when x = 0 is the case. Also, we don't have issues such as division by zero errors that could arise. It's a bit curious why your teacher put in that condition.
Answer:
4.91666666667
Step-by-step explanation:
1 1/3 + 1 5/6 + 1 3/4 = 4.91666666667
Answer:
4.58257
Step-by-step explanation:
That is the square root of 21, so if there's a point about there, then choose it.
Answer:
2813 English books
Step-by-step explanation:
Hindi books are 42% of 4850
42 ÷ 100 = 0.42
0.42 × 4850 = 2037 Hindi books
number of English books = total number of Hindi and English books - number of hindi books
4850 - 2037 = 2813 English books