Question

factorise the following question :81p^2-16

Answer 1

=>81p^2-16

=>(9p)^2 -(4)^2

since [(a^2-b^2=(a+b)(a-b)]

=>(9p+4)(9p-4)------(answer)

hope it helps!!

Answer 2

81p^2 -16
81p^2 = 16
p^2 = 16/81
p = + 4/9 or p = -4/9
so the factors are (p + 4/9) and (p - 4/9)
or (9p + 4) (9p - 4)