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.
Answer:
BEC = C. 50
BCD = A. 120
Step-by-step explanation:
BEC
65 + 65 = 130
180 - 130 = 50
BCD = 180 - 60 = 120
BEC is 50
Answer:
option 4
Step-by-step explanation:
(f*g)(x) =(x² + x+ 1)*(x² - x -1)
= x²*(x² - x -1) + x(x² - x -1) + 1*( x² - x -1)
= x²*x² - x²*x -x²*1 + x*x² - x*x -x*1 + x² - x -1
= x⁴ - x³ - x² +x³ - x² - x + x² - x -1
= x⁴ - x³ + x³ - x² - x² + x² - x - x - 1
= x⁴ - x² - 2x - 1
Ordering laptops. Much more expensive. Higher consequences.
Word form: one hundred one and six hundredths.
expanded form: 100+1+0.06