Find all the pairs of natural number

Question

the difference of whose squares is 45

Answer 1

a^2-b^2= 45

(a+b)(a-b)= 45

(a+b)(a-b= 45*1

a+b=45

a-b=1

a= 23, b=22

 

(a+b)(a-b)= 15*3

a+b=15

a-b=3

a=9, b=6

 

(a+b)(a-b)= 9*5

a+b=9

a-b=5

a=7 b=2

 

I think that's all of them.