Question

If 3² + 4² = c², then c equals

Answer 1

The answer is 5

Explanation:

c²=3²+4²

c²=9+16

c²=25

`\sqrt{ {c}^(2) } = √(25)`

c=5

Answer 2

The value of c is :

↬ c = 5, c = -5

Solution:

First off, we should square the numbers:

`\sf{3^2+4^2=c^2}`

`\sf{9+16=c^2}`

`\sf{25=c^2}`

Now I square-root each side :

`\sf{5=c}`

`\sf{-5=c}`

This means that :

`\sf{c=5,\:c=-5}`

How did this happen? We should know that once we take the square root of a number, we end up with two solutions that are opposites of each other. This phenomenon is explained below.

When we square 5, we get 25. When we square -5, we also get 25.

So then, when taking the square root of 25, we get both 5 and -5. And now, we know why.

Hence, c = 5 and c = -5.