Question

Factorise a^7 - ab^6

Answer 1

given,

${a}^{7} - {ab}^{6}$
taking out common factor, we have,


$a( {a}^{6} - {b}^{6} )$
using the identity a² - b² = (a - b)(a + b),

we have,

$a(( { {a}^{3}) }^{2} - { ({b}^{3}) }^{2} )$


$= a( {a}^{3} - {b}^{3} )( {a}^{3} + {b}^{3} )$
is the answer