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]`

Answer 1

`[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