Question

81-4x^2

please explain how you got your answer

Answer 1

Answer:

b = 2 x .  

(9+2x) (9-2x)

Step-by-step explanation:

Since both terms are perfect squares, factor using the difference of squares formula,  a 2 − b 2 = ( a + b ) ( a − b )

Answer 2

Answer:

Step-by-step explanation:

81 - 4$x^{2}$

         notice how this is difference of squares, meaning you can simplify

(9-2x) (9+2x)

         if the question is asking to find roots, then you just set this equal to 0, and that means that either 9-2x or 9+2x must be equal to 0.

9-2x = 0                    9+2x = 0

9 = 2x                       9 = -2x

x = 4.5                      x = -4.5

Therefore the two roots of this equation are ±4.5