Question

Q.22 plz solve it's urgent plz

Answer 1

All will be cancelled  and answer will be one

Answer 2

The identity to be used here is

${a}^{3} + {b}^{3} = (a + b)( {a}^{2} - ab + {b}^{2} )$

Put a = 0.87 and b = 0.13 and expand the numerator using the identity

$LHS \\ \\ = \frac{ {(0.87)}^{3} + {(0.13)}^{3} }{ {(0.87)}^{2} - 0.87 \times 0.13 + {(0.13)}^{2} } \\ \\ = \frac{ (0.87 + 0.13)\ [{(0.87)}^{2} - 0.87 \times 0.13 + {(0.13)}^{2}]}{ {(0.87)}^{2} - 0.87 \times 0.13 + {(0.13)}^{2} }$

$= 0.87 + 0.13 \\ \\ = 1\\ \\ = RHS$