Advertisements
Advertisements
Question
Write the following cube in expanded form:
(2a – 3b)3
Advertisements
Solution
It is known that,
(a + b)3 = a3 + b3 + 3ab(a + b) and (a − b)3 = a3 − b3 − 3ab(a − b)
(2a − 3b)3 = (2a)3 − (3b)3 – (3 × 2a × 3b)(2a – 3b)
= 8a3 – 27b3 – 18ab(2a – 3b)
= 8a3 – 27b3 – 36a2b + 54ab2
APPEARS IN
RELATED QUESTIONS
Expand the following, using suitable identity:
(3a – 7b – c)2
Expand the following, using suitable identity:
`[1/4a-1/2b+1]^2`
Write in the expand form: `(2x - y + z)^2`
If \[x - \frac{1}{x} = 5\], find the value of \[x^3 - \frac{1}{x^3}\]
If 3x − 2y = 11 and xy = 12, find the value of 27x3 − 8y3
Evaluate the following:
(98)3
Find the value of 27x3 + 8y3, if 3x + 2y = 14 and xy = 8
Simplify of the following:
(x+3)3 + (x−3)3
Simplify of the following:
Find the following product:
If a + b = 8 and ab = 6, find the value of a3 + b3
Find the following product:
(3x + 2y + 2z) (9x2 + 4y2 + 4z2 − 6xy − 4yz − 6zx)
If \[x + \frac{1}{x}\] 4, then \[x^4 + \frac{1}{x^4} =\]
If \[x^4 + \frac{1}{x^4} = 194,\] then \[x^3 + \frac{1}{x^3} =\]
Find the square of : 3a + 7b
If x + y = `7/2 "and xy" =5/2`; find: x - y and x2 - y2
Evaluate, using (a + b)(a - b)= a2 - b2.
399 x 401
If a2 + b2 + c2 = 41 and a + b + c = 9; find ab + bc + ca.
Simplify:
(x + y - z)2 + (x - y + z)2
Using suitable identity, evaluate the following:
9992
