Step-by-step explanation:
put it in least to greatest and then put your fingers on the opposite side of the numbers and count down at the same time
Answer:
12
x^2 - a
If a is a perfect square we could factor
x^2 - b^2 = (x-b)(x+b)
So a cannot be 36,49,81 since they are perfect squares
a must be 12
Is this a question??
106,719
8
using a= 6 c=10