Answer:
D
Step-by-step explanation:
complementary means it equals 90
Answer:
Step-by-step explanation:
It must end in 
(divisible by 2 rule) and the digits must sum to a multiple of 9(divisible by 9 rule).
The digit sum is 
.
We want to make 
as low as possible because it's a higher digit than 
.
If is as low as possible, we have that the sum is 
. Uh-oh. has to be even! So 
doesn't work.
If 
, we have that the sum is 
. Yay!
So, the answer is 
Hope you have got the answer to this question. If not, here it is:
(a² -b²) +(a+b)
(a+b)(a-b)+(a+b)
(a+b)(a-b+1)
