Advertisements
Advertisements
प्रश्न
Select the correct answer from the given alternatives.
If the coefficient of x2 and x3 in the expansion of (3 + ax)9 are the same, then the value of a is
पर्याय
`-7/9`
`-9/7`
`7/9`
`9/7`
उत्तर
`9/7`
Explanation;
tr+1= 9Cr(3)9–r(ax)r = 9Cr39–rarxr
∴ 9C2 × 37 × a2 = 9C3 × 36 × a3
∴ `(9!)/(2!7!) xx 3 = (9!)/(3!6!) xx "a"`
∴ a = `9/7`
APPEARS IN
संबंधित प्रश्न
Find the middle term in the expansion of `(x/y + y/x)^12`
Find the middle terms in the expansion of `(x^2 + 1/x)^7`
Find the middle term in the expansion of `(x^2 - 2/x)^8`
Find the middle term in the expansion of `(x/"a" - "a"/x)^10`
Find the middle terms in the expansion of `(x^4 - 1/x^3)^11`
Select the correct answer from the given alternatives.
The middle term in the expansion of (1 + x)2n will be :
Select the correct answer from the given alternatives.
In the expansion of (3x + 2)4, the coefficient of the middle term is
Select the correct answer from the given alternatives.
The coefficient of the 8th term in the expansion of (1 + x)10 is:
Answer the following:
Find the middle term (s) in the expansion of `((2"a")/3 - 3/(2"a"))^6`
Answer the following:
Find the middle term (s) in the expansion of `(x - 1/(2y))^10`
Answer the following:
Find the middle term (s) in the expansion of (x2+ 2y2)7
Answer the following:
Find the middle term (s) in the expansion of `((3x^2)/2 - 1/(3x))^9`
Answer the following:
If the middle term in the expansion of `(x + "b"/x)^6` is 160, find b
The term independent of x in the expansion of `(root(6)(x) - 1/root(3)(x))^9` is ______.
