Question

X^2-16=0 solve for all real values of x

Answer 1

Hi there! Use the difference of two squares formula below:

`\large \boxed{ {x}^(2) - {y}^(2) = (x + y)(x - y)}`

You need to know that what number times itself and get 16. 16 comes from 4×4 or 4².

Then,

`\large{ {x}^(2) - 16 = (x + 4)(x - 4)}`

`\large{(x + 4)(x - 4) = 0}`

Solve the equation for all real values of x.

`\large{x = 4, - 4}`

If you don't like using a formula. You can do this:

`\large{ {x}^(2) - 16 = 0} \\ \large{ {x}^(2) = 16} \\ \large{x = \pm √(16) } \\ \large{x = \pm 4}`

If you remember the square root well, the square root of 16 is 4×4. Pull out the two 4's and thus the square root of 16 is 4.

For the square both sides method above (second method), we can define that:

`\large \boxed{ \large{ {x}^(2) = a \longrightarrow x = \pm a }}`

Answer

• x = 4,- 4 (You can answer x = ±4