Show that x^2-y^2= (x+y)(x-y) with venn diagram ​

Really need on these. i have no idea what to do

Asequence is defined recursively by the formula  f(n  +  1)  =  f(n)  +  3 . the first term of the sequence is  –4. what is the next term in the sequence? –7–117

Asquare is dilated by a scale factor of 1.25 to create a new square. how does the area of the new square compare with the area of the original square? a)the area of the new square is 1.25 times the area of the original square. b)the area of the new square is 2.50 times the area of the original square. c)the area of the new square is 1.252 times the area of the original square. d)the area of the new square is 1.253 times the area of the original square.