Remark
Many calculators have a key that will do this in one step. Mine is one of them. So let's start with the answer and then we'll do it the long way.
9C3 = 84. You put it into your calculator as 9 2nF nCr 3 =
Solution

3*4*7 = 84 which is what you set out to show.
Regroup terms
Add 2x to both sides
Simplify 4 - x + 2x to 4 + x
subtract 4 from both sides
subtract -6 - 4.
Answer: x = -10
Answer:
56.
Step-by-step explanation:
46+10=56
Answer:
B. (2 + 5).
Step-by-step explanation:
18 + 45 = 63
The prime factors of 63 = 3*3*7
So 63 is a multiple of 7.
The answer is (2 + 5) (=7).