Advertisements
Advertisements
Question
Simplify using following identity : `( a +- b )(a^2 +- ab + b^2) = a^3 +- b^3`
( 2x + 3y )( 4x2 + 6xy + 9y2 )
Advertisements
Solution
( 2x + 3y )( 4x2 + 6xy + 9y2 )
= ( 2x + 3y )[ (2x)2 - (2x)(3y) + (3y)2 ]
= (2x)3 + (3y)3
= 8x3 + 27y3
APPEARS IN
RELATED QUESTIONS
Simplify : ( x + 6 )( x + 4 )( x - 2 )
Simplify : ( x - 6 )( x - 4 )( x + 2 )
Simplify using following identity : `( a +- b )(a^2 +- ab + b^2) = a^3 +- b^3`
`(a/3 - 3b)(a^2/9 + ab + 9b^2)`
Find : (a + b)(a + b)
Find : (a + b)(a + b)(a + b)
Prove that : x2+ y2 + z2 - xy - yz - zx is always positive.
If a + b = 11 and a2 + b2 = 65; find a3 + b3.
If x = 3 + 2√2, find :
(i) `1/x`
(ii) `x - 1/x`
(iii) `( x - 1/x )^3`
(iv) `x^3 - 1/x^3`
Using suitable identity, evaluate (97)3
Evaluate :
`[1.2 xx 1.2 + 1.2 xx 0.3 + 0.3 xx 0.3 ]/[ 1.2 xx 1.2 xx 1.2 - 0.3 xx 0.3 xx 0.3]`
