Answer:
C
Step-by-step explanation:
You are choosing 3 from a total of 12. Order does not matter. So you are working with combinations. The answer symbolically is
12C3
12C3 = 12!/(9!3!)
12C3 = 12 * 11 * 10 * 9!/(9! 3!)
12C3 = 12 * 11 * 10/6
12C3 = 2 * 11 * 10
12C3 = 220
So,
9*27 + 2*31 - 28 = n
We use PEMDAS.
Multiply from left to right.
243 + 2*31 - 28 = n
243 + 62 - 28 = n
Add or subtract from left to right.
305 - 28 = n
277 = n
3ˣ (x² - 3)
Basically, just multiply everything together.
Step 1 : 3x × x² = 3x³ because when multiplying exponents, all you're really doing is adding them on top. So, x + 2x = 3x! But, they are exponents, so you get 3x³.
Step 2 : 3x ˣ × (-3) = -9ˣ
Now, our new question is : 3x³ - 9x
You wouldn't simplify this because x³ is NOT the same as x.
~Hope I helped!~
