The expression cannot be factored.
15.556 to three decimal places
15.46482452
(a + 2b)(a + 2b)
plus multiplied by plus is plus
== ==
14.777
First you do the square root, then the multiplication, then the addition.
9x2 + 24xy + 16y2 = 9x2 + 12xy + 12xy + 16y2 = 3x(3x + 4y) + 4y(3x + 4y) = (3x + 4y)*(3x + 4y) = (3x + 4y)2
factor it
(x + 3)(x + 3)
5 - x^2 = (the square root of 5 minus x)(the square root of 5 plus x)
(2x-5) (x-1)