Why can't sqrt(45) simplify to 5sqrt(9)? Please explain well. Thanks!

Hi Mellie, it is great to see you one the forum again :)

Thanks Chris,

Looking at it the other way round

\(\sqrt{45}=\sqrt{9*5}=\sqrt9 * \sqrt5=3*\sqrt5 =3\sqrt5 \)

I like Chris's answer better though :)

Let's suppose that it could be....then

5√9 = 5*3  = 15.........and this must mean that.....

15 = √45       square both sides

225  = 45     and this clearly isn't true

Thanks CPhill and Melody!