Question

Prove that - 0.87*0.87*0.87 +0.13*0.13*0.13 /0.87*0.87 - 0.87*0.13 + 0.13*0.13 = 1

Answer 1

we know a³ + b³ = (a+b) (a² - ab + b²)

here   a = 0.87  and   b = 0.13        and  a + b = 1

(0.87³ + 0.13³ ) / [ 0.87² - 0.87 * 0.13 + 0.13² ] 
=  1 * (0.87² - 0.87 * 0.13 + 0.13² ) / [ 0.87² - 0.87 * 0.13 + 0.13² ]
 = 1

Answer 2

Answer:

we know a³ + b³ = (a+b) (a² - ab + b²)

here   a = 0.87  and   b = 0.13        and  a + b = 1

(0.87³ + 0.13³ ) / [ 0.87² - 0.87 * 0.13 + 0.13² ]  

=  1 * (0.87² - 0.87 * 0.13 + 0.13² ) / [ 0.87² - 0.87 * 0.13 + 0.13² ]

= 1

I HOPE IT HELPS YOU.