So, i did this,
7.8*10=70
and then add 12
i got 82
did this help??
Answer:
It is correct.
Step-by-step explanation:
Answer:
The fourth term of the expansion is -220 * x^9 * y^3
Step-by-step explanation:
Question:
Find the fourth term in (x-y)^12
Solution:
Notation: "n choose k", or combination of k objects from n objects,
C(n,k) = n! / ( k! (n-k)! )
For example, C(12,4) = 12! / (4! 8!) = 495
Using the binomial expansion formula
(a+b)^n
= C(n,0)a^n + C(n,1)a^(n-1)b + C(n,2)a^(n-2)b^2 + C(n,3)a^(n-3)b^3 + C(n,4)a^(n-4)b^4 +....+C(n,n)b^n
For (x-y)^12, n=12, k=3, a=x, b=-y, and the fourth term is
C(n,3)a^(n-3)b^3
=C(12,3) * x^(12-3) * (-y)^(3)
= 220*x^9*(-y)^3
= -220 * x^9 * y^3
From the information we have, we know that each book costs 1.20 dollars. So we shall say this price is at 100% .
Now we need to form an equation to get the percentage when the books are sold at 0.80 dollars.
100% = 1.20
x = 0. 80
Where x is the new percentage when the sale is at 0.80 dollars.
We cross multiply the equation:
1.20 *x = 0.80 * 100
1.2x = 80
x = 80/1.2
x = 66.7%
Round off 66.7 to the nearest tenth we get 67%
The notebooks are sold at 67% (of the original cost).
Answer:
2/4
Step-by-step explanation:
by
