Advertisements
Advertisements
Question
The coefficient of x in the expansion of (x + 3)3 is ______.
Options
1
9
18
27
Advertisements
Solution
The coefficient of x in the expansion of (x + 3)3 is 27.
Explanation:
Consider the expression:
(x + 3)3
Use the identity: (a + b)3 = a3 + b3 + 3ab(a + b)
(x + 3)3 = x3 + 33 + 3 × x × 3(x + 3)
= x3 + 27 + 9x2 + 27x
Since, the coefficient of x is 27.
APPEARS IN
RELATED QUESTIONS
Expand the following, using suitable identity:
(3a – 7b – c)2
Evaluate the following using suitable identity:
(99)3
Factorise the following:
27 – 125a3 – 135a + 225a2
If \[x + \frac{1}{x} = 3\], calculate \[x^2 + \frac{1}{x^2}, x^3 + \frac{1}{x^3}\] and \[x^4 + \frac{1}{x^4}\]
Find the following product:
(4x − 5y) (16x2 + 20xy + 25y2)
Find the following product:
\[\left( \frac{x}{2} + 2y \right) \left( \frac{x^2}{4} - xy + 4 y^2 \right)\]
If x = 3 and y = − 1, find the values of the following using in identify:
\[\left( \frac{x}{7} + \frac{y}{3} \right) \left( \frac{x^2}{49} + \frac{y^2}{9} - \frac{xy}{21} \right)\]
If x = −2 and y = 1, by using an identity find the value of the following
If \[a^2 + \frac{1}{a^2} = 102\] , find the value of \[a - \frac{1}{a}\].
If \[x^4 + \frac{1}{x^4} = 623\] then \[x + \frac{1}{x} =\]
Find the square of : 3a + 7b
Use the direct method to evaluate :
(0.5−2a) (0.5+2a)
Expand the following:
(2p - 3q)2
Simplify by using formula :
(x + y - 3) (x + y + 3)
If a - b = 10 and ab = 11; find a + b.
If m - n = 0.9 and mn = 0.36, find:
m2 - n2.
If a2 + b2 + c2 = 41 and a + b + c = 9; find ab + bc + ca.
If `"a"^2 + (1)/"a"^2 = 14`; find the value of `"a" + (1)/"a"`
Using suitable identity, evaluate the following:
101 × 102
Give possible expressions for the length and breadth of the rectangle whose area is given by 4a2 + 4a – 3.
