Question

Plz answer
Factorise it
a²-81(b-c)²

Answer 1

${a}^{2} - 81 {(b - c)}^{2}$

=> $( {a}^{} ) {}^{2} - (9(b - c)) {}^{2}$

=>[a-9(b-c)] [ a+9(b+c)]

=> (a-9b+9c)(a+9b+9c)

Cheers!!