(sqrt7+9)(sqrt7-3)

  • 0 votes

Surds. Is the answer 6*sqrt7-20?

Posted Sat 9th June, 2012 @ 12:53 by Hoosierette

3 Answers

  • 2 votes

7+9sqrt7-3sqrt7-27

6sqrt7-20

So yes!

Answered Sat 9th June, 2012 @ 13:17 by Dilly
  • 0 votes

I agree with @ Dilly! (:

@Elisha Mehta, you have got your method wrong. 

Answered Sat 9th June, 2012 @ 17:46 by Nishat Ahmed
  • -2 votes

First I would split the equation into brackets: (7+9sqrt)x(7-3sqrt)x(7-27)

As you can see part c can be simplified to (-21)

Now we can multiply part a with b: 49+2 21sqrt-27 sqrt -21

Therefore your final answer is 28+2 21sqrt- 27sqrt.

This question seemed a bit dodgy to me but I hope my answer helps!

Answered Sat 9th June, 2012 @ 15:00 by girlyrainbow