Thread: Radicals?

Hey guys, I was away when my Principals 10 class did radicals.. now I have no clue what I'm doing & I have a mid-term next week yay!
Can someone please help me?

thanks so much

Originally Posted by ccynd

Hey guys, I was away when my Principals 10 class did radicals.. now I have no clue what I'm doing & I have a mid-term next week yay!
Can someone please help me?

thanks so much

do you have a specific question?

I have a few haha.

Uhh lets see, here's one.. I just figured how to do the √ thing haha.

its 2√20 - √8 + √18 - 3√45


I got an anwser of -5√5-5√2... buttt I think I got it wrong.

here are my steps :S

2√4 x 5 - √ 4 x 2 + √ 9 x 2 - 3 √ 9 x 5 =

2 x 2 √5 - 2 √2 + 3√2 - 3 x 3 √5=

4√5 - 2√2 + 3√2 - 9√5=

-5√5 - 5√2

Originally Posted by ccynd

I have a few haha.

Uhh lets see, I dont know how to do the "square root" symbol thing.. sooo I'll put this instead *

its 2*20 - *8 + *18 - 3*45


I got an anwser of -5*5-5*2... buttt I think I got it wrong.

Here, tell me if you don't understand what i did?

Originally Posted by ccynd

I have a few haha.

Uhh lets see, here's one.. I just figured how to do the √ thing haha.

its 2√20 - √8 + √18 - 3√45


I got an anwser of -5√5-5√2... buttt I think I got it wrong.

here are my steps :S

2√4 x 5 - √ 4 x 2 + √ 9 x 2 - 3 √ 9 x 5 =

2 x 2 √5 - 2 √2 + 3√2 - 3 x 3 √5=

4√5 - 2√2 + 3√2 - 9√5=

-5√5 - 5√2

you are right up to the second to last step.

how do you add -2sqrt(2) and +3sqrt(2) and get -5sqrt(2)?

I really don't know.. there could've been something wrong when I wrote it down.. it tends to happen..

but I was on the right track, right?

I have another question too (if you don't mind)


(exp)3√16 + (exp)3√54 {is it the same, but you just keep the same exponent?... }

Originally Posted by ccynd

I really don't know.. there could've been something wrong when I wrote it down.. it tends to happen..

but I was on the right track, right?

I have another question too (if you don't mind)


(exp)3√16 + (exp)3√54 {is it the same, but you just keep the same exponent?... }

yes, you were on the right track, but you made a rookie mistake, you added -2 and + 3 and got -5!

what do you mean by (exp)3? do you mean to write the cube root?