Answer: 15
Step-by-step explanation:
(r+1)th term of
is given by:-

For
, n= 6

![=\ \dfrac{6!}{4!2!}a^4b^2\ \ \ [^nC_r=\dfrac{n!}{r!(n-r)!}]\\\\=\dfrac{6\times5\times4!}{4!\times2}a^4b^2\\\\=3\times5a^4b^2\\\\ =15a^4b^2](https://tex.z-dn.net/?f=%3D%5C%20%5Cdfrac%7B6%21%7D%7B4%212%21%7Da%5E4b%5E2%5C%20%5C%20%5C%20%5B%5EnC_r%3D%5Cdfrac%7Bn%21%7D%7Br%21%28n-r%29%21%7D%5D%5C%5C%5C%5C%3D%5Cdfrac%7B6%5Ctimes5%5Ctimes4%21%7D%7B4%21%5Ctimes2%7Da%5E4b%5E2%5C%5C%5C%5C%3D3%5Ctimes5a%5E4b%5E2%5C%5C%5C%5C%20%3D15a%5E4b%5E2)
Hence, the coefficient of the third term in the binomial expansion of
is 15.
Answer:
=25x-7
Step-by-step explanation:
Answer:
Length: 20 or 40 feet
Width: 40 or 20 feet
Step-by-step explanation:
Area = 800 = length*width = x*(60-x)= 60x - x^2
- x^2 + 60x - 800 = 0
x = 20
Or x = 40
So length can be either 20 feet or 40 feet and width can be 40 (60-20) or 20 (60-40)
Answer for Q.1 = 4/9
Answer for Q2. = 2/3