Need some help!

$$\\3a \sqrt{45 b^3} + 2a \sqrt{80 b^2} - 7 \sqrt{20 a^2 b^3}\\\\
3a \sqrt{9b^2* 5b} + 2a \sqrt{16 b^2*5} - 7 \sqrt{4 a^2 b^2*5b}\\\\
3a*3b \sqrt{5b} + 2a *4b\sqrt{5} - 7*2ab \sqrt{5b}\\\\
9ab\sqrt{5b} + 8ab\sqrt{5} - 14ab \sqrt{5b}\\\\
9ab\sqrt{5b} - 14ab \sqrt{5b}+ 8ab\sqrt{5} \\\\
-5ab \sqrt{5b}+ 8ab\sqrt{5} \\\\
8ab\sqrt{5} -5ab \sqrt{5b}\\\\$$

3a √45 b³ + 2a √80 b² - 7 √20 a² b³ 

$$\\3ab^3\sqrt{9*5}+2ab^2\sqrt{16*5}-7a^2b^3\sqrt{4*5}\\\\
9ab^3\sqrt{5}+8ab^2\sqrt{5}\;-14a^2b^3\sqrt{5}\\$$

I had a copy error in mine but yours is not correct either unless some of those letters are meant to be under the square root signs     

Thanks Melody! I only have to simplify completely.

I did this on an online calculator and received a different answer 

8ab√5 - 5ab√5b

some of your letters must have been under the square root sign

That is why brackets are so important :)

Ok, so this is exactly how it was stated

oops 

The letters are meant to be under the square root sign