x2 - 16 = (x + 4)(x - 4)
x2 - 16 is the difference of two squares:
a2 - b2 factorises as (a + b)(a -b), thus:
x2 - 16 = x2 - 42
= (x + 4)(x - 4)
Chat with our AI personalities
75r^2-48 You can take out 3.So... 3(25r^2-16) 3-parenthesis-25r squared-minus-16-parenthesis (:
It is the difference of squares. (x-4) and (x+4) <--- answer
If the question could more exactly be phrased as, "What is the value of x when 9x2 - 16 = 0", the answer is, x = 4 or -4. This answer can be found by factoring 9x2 - 16 into (3x + 4)(3x - 4) and setting each factor equal to zero.
In one bracket, write 16 times the square root of 2 minus 3x. In the other one, write 16 times the square root of 2 plus 3x.
(x4 - 16) = (x2 + 4) (x2 - 4) = (x2 + 4) (x + 2) (x - 2)