Chapter 9.5, Problem 50PFA

To determine

Find the value

Answer to Problem 50PFA

4

Explanation of Solution

Given Information: $x^2-20$

Formula Used: $a^2+2ab+b^2={(a+b)}^2$

Calculation:

  $x^2-20$

Now, add 4 to make complete square

  $x^2-20+4$

So,

  $x^2-16=0$

Now, simplify

  $x^2=16$

Square root both sides

  $x=\pm 4$

So, after add 4 can make complete square.