Question

One solution of x^2-25=0 is 5. What is the other solution? Enter the correct answer.

Answer 1

Answer:

The other solution: x = -5

Step-by-step explanation:

$x^2-25=x^2-5^2\qquad\text{use}\ a^2-b^2=(a-b)(a+b)\\\\=(x-5)(x+5)\\\\x^2-25=0\to(x-5)(x+5)=0\iff x-5=0\ \vee\ x+5=0\\\\x-5=0\qquad\text{add 5 to both sides}\\x=5\\\\x+5=0\qquad\text{subtract 5 from both sides}\\x=-5$