Question

1.factorise
(a)B²-100​

Answer 1

$= b ^{2} - 100 \\ = b ^{2} - 10 ^{2} \\ = (b - 10)(b + 10)$

hope it will help u ✨

Answer 2

⟹B²-100

⟹B²-(10)²

⟹(B+10)( B-10). [a²-b²=(a + b) (a - b)]