Question

A classmate is having trouble factoring special-case polynomials.point out the errors she has made, and write a brief suggestion to help her with similar problems
a.4a^2-100
=(2a-10)(2a-10)
=(2a-10)^2
b.81m^4+72m^2n++16n^2
=(9m^2+8n)(9m^2+8n)
=(9m^2+8n^2)
c.a^10b^4-16
=(a^5b^2-16)
=)a^5b^2-4)(a^5b^2+4
d.4d^2+36d+81=
(2d+9)(2d-9)
metal+fan