Factorising the Difference of Two Squares

Question 1:

x2 49
x + 7 x 7

Question 1:

x2 64
x + 8 x 8

Question 1:

x2 81
x + 9 x 9

Question 1:

x2 25
x + 5 x 5

Question 1:

9 x2 100
3 x + 10 3 x 10

Question 1:

16 x2 100
4 x + 10 4 x 10