9 squared = 81 4 squared = 16 (81)(16) = 1296 (1296)(8) = 10368 sq. root of 10368 = 101 101 - 1 = 100
9 x 9 = 81 9 squared = 81 3 squared times 3 squared = 81
x2-81=(x-9)(x+9) Factors: x-9, x+9
9 squared is 81. Two digits lower than 81 is 79. 79 is a prime number. Its only factors are one and itself. That does not compute. 78 has 26 and 6 as factors. 78 is three digits lower than 81. That does not compute.
16, 81, 625 and so on. Prime numbers to the 4th power.
81 x 2 - 16 = 146
4x2/81 = 1 - 16x2/25100x2 = 25*81 - 16*81x21396x2 = 2025x2 = 2025/1396x = +/- 1.2044, approx.
9 squared is 81 and 16 squared is 256
x2-81 = (x-9)(x+9)
9x2 - 6xy + y2 - 81 = (3x - y)2 - 92 = (3x - y - 9)(3x - y + 9)
78 minus78
79, -79
(9 - 5u)(9 + 5u)
9x2 - 6xy + y2 - 81 = (3x - y)2 - 81 = (3x - y - 9)*(3x - y + 9)
The answer? There is no "answer" There cannot be an answer because they are all different. In order to make calculations, the variables have to be the same. x squared, xy, y squared are the variables, and none of them match. Therefore your "answer" must look like this: 9x squared - 6xy + y squared - 81. Hope I Helped :D
81
I believe it is prime as you have written it. change the end to + 81 and it factors as (2x - 1)(x-9)(x+9)