QUESTION 1
We want to expand
.
We apply the binomial theorem which is given by the formula
.
By comparison,
.
We substitute all these values to obtain,
.
We now simplify to obtain,
.
This gives,
.
Ans:C
QUESTION 2
We want to expand
.
We apply the binomial theorem to obtain,
.
We simplify to get,
.
We simplify further to obtain,
![(x+2y)^4=x^4+8x^{3}y+24x^{2}y^2+32x^{1}y^3+16y^4](https://tex.z-dn.net/?f=%28x%2B2y%29%5E4%3Dx%5E4%2B8x%5E%7B3%7Dy%2B24x%5E%7B2%7Dy%5E2%2B32x%5E%7B1%7Dy%5E3%2B16y%5E4)
Ans:B
QUESTION 3
We want to find the number of terms in the binomial expansion,
.
In the above expression,
.
The number of terms in a binomial expression is
.
Therefore there are 21 terms in the binomial expansion.
Ans:C
QUESTION 4
We want to expand
.
We apply the binomial theorem to obtain,
.
We simplify to get,
.
We simplify further to obtain,
![(x+2y)^4=x^4-4x^{3}y+6x^{2}y^2-4x^{1}y^3+y^4](https://tex.z-dn.net/?f=%28x%2B2y%29%5E4%3Dx%5E4-4x%5E%7B3%7Dy%2B6x%5E%7B2%7Dy%5E2-4x%5E%7B1%7Dy%5E3%2By%5E4)
Ans: C
QUESTION 5
We want to expand ![(5a+b)^5](https://tex.z-dn.net/?f=%285a%2Bb%29%5E5)
We apply the binomial theorem to obtain,
.
We simplify to obtain,
.
This finally gives us,
.
Ans:B
QUESTION 6
We want to expand
.
We apply the binomial theorem to obtain,
.
We simplify to get,
.
This will give us,
.
Ans:A
QUESTION 7
We want to find the 6th term of
.
The nth term is given by the formula,
.
Where ![r=5,n=7,b=-y](https://tex.z-dn.net/?f=r%3D5%2Cn%3D7%2Cb%3D-y)
We substitute to obtain,
.
.
Ans:D
QUESTION 8.
We want to find the 6th term of ![(2x-3y)^{11}](https://tex.z-dn.net/?f=%282x-3y%29%5E%7B11%7D)
The nth term is given by the formula,
.
Where ![r=5,n=11,a=2x,b=-3y](https://tex.z-dn.net/?f=r%3D5%2Cn%3D11%2Ca%3D2x%2Cb%3D-3y)
We substitute to obtain,
.
.
Ans:D
QUESTION 9
We want to find the 6th term of
.
The nth term is given by the formula,
.
Where ![r=5,n=8,a=x,b=y](https://tex.z-dn.net/?f=r%3D5%2Cn%3D8%2Ca%3Dx%2Cb%3Dy)
We substitute to obtain,
.
.
Ans: A
We want to find the 7th term of
.
The nth term is given by the formula,
.
Where ![r=6,n=8,a=x,b=4](https://tex.z-dn.net/?f=r%3D6%2Cn%3D8%2Ca%3Dx%2Cb%3D4)
We substitute to obtain,
.
.
Ans:A