Answer:

Step-by-step explanation:
<u>Binomial Series</u>

<u>Factorial</u> is denoted by an exclamation mark "!" placed after the number. It means to multiply all whole numbers from the given number down to 1.
Example: 4! = 4 × 3 × 2 × 1
Therefore, the fourth term in the binomial expansion (a + b)⁶ is:






Are you given an equation?
Answer:X=9
Step-by-step explanation:
x+18=3x
18=2x
x=9
See, pls, offered explanation:
1) the both equations are linear function, it means system made up of the both equation has the only solution.
2) if to prove this:

Answer: one solution.