Question

помогите умоляюююю!!!!!!

Answer 1

$\displaystyle 1)16a^2-25b^2=4^2a^2-5^2b^2=(4a)^2-(5b)^2=(4a-5b)(4a+5b)\\\\2)y^2-4y+4=y^2-2*y&*2+2^2=(y-2)^2\\\\3)8x^4-xy^3=x(8x^3-y^3)=x(2x-y)(4x^2+2xy+y^2)\\\\4)(7x-7)^2-(x+2)^2=(7x-7-(x+2))(7x-7+(x+2))=\\\\(7x-7-x-2)(7x-7+x+2)=(6x-9)(8x-5)=3(2x-3)(8x-5)$