Advertisements
Advertisements
Question
Evaluate :
`[0.8 xx 0.8 xx 0.8 + 0.5 xx 0.5 xx 0.5]/[0.8 xx 0.8 - 0.8 xx 0.5 + 0.5 xx .5]`
Solution
`[0.8 xx 0.8 xx 0.8 + 0.5 xx 0.5 xx 0.5]/[0.8 xx 0.8 - 0.8 xx 0.5 + 0.5 xx .5]`
Let 0.8 = a and 0.5 = b
Then, the given expression becomes
`[ a xx a xx a + b xx b xx b]/[a xx a - a xx b + b xx b]`
= `[ a^3 + b^3 ]/[a^2 - ab + b^2 ]`
= `[( a + b )( a^2 - ab + b^2 )]/[a^2 - ab + b^2]`
= a + b
= 0.8 + 0.5
= 1.3
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`
( 2x + 3y )( 4x2 + 6xy + 9y2 )
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)(a + b)
Find : (a - b)(a - b)(a - b)
Prove that : x2+ y2 + z2 - xy - yz - zx is always positive.
If x = 3 + 2√2, find :
(i) `1/x`
(ii) `x - 1/x`
(iii) `( x - 1/x )^3`
(iv) `x^3 - 1/x^3`
If a - 2b + 3c = 0; state the value of a3 - 8b3 + 27c3.
Using suitable identity, evaluate (104)3
