Question

10. Factorise
1.343y³-1000​

Answer 1

Answer:

$using \: identity \: {x}^{3} - {y}^{3} = (x - y)( {x}^{2} +xy + {y}^{2} )$

${343y}^{3} - 1000 \\ = 7 \times 7 \times 7 {y}^{3} - 10 \times 10 \times 10 \\ = {(7y)}^{3} - {(10)}^{3} \\ (7y - 10)( {(7y)}^{2} + (7y)(10) + {(10)}^{2} ) \\ = (7y - 10)(49 {y}^{2} + 70y + 100)$