SRL Archive - Mathematics

It's my middle of the year exam (Mid Exam, or Mid Term) and I'm taking algebra/trigonometry but I need some help.

For one I'll just post a problem

Which expression is equivalent to (√(7) + √(2)) / (√(7) - √(2))

The answer is C but i need to know how to get to that answer without just plugging it into my calculator(plug in all the choices).

A) (11 + √(2)) / 14
B) 9/5
C) (9 + 2√(14)) / 5
D) - 1

Edit: I understand that problem now, go to my next post for the new one.
Should of just taken a picture but whatever, I'd really appreciate if someone could add my msn [email]aarondawg14@yahoo.com[/email] and give me some more help :)

Could give you something in RS.

Try plugging this: (√(7) + √(2)) / (√(7) - √(2))

… into …

This: http://www.wolframalpha.com

… and then see if what it throws back at you gives you any clues. :)

I did that earlier which gave me the answer I needed, but I still am not sure how to get that answer.

I multiply both the denominator and numerator by √7 + √2 and the bottom comes out to be 7 - 2 which is 5, but I don't understand how they get the numerator.

Edit: Wow, I'm stupid. I understand this problem. Someone here is helping me on MSN. If i get anymore problems I'll be sure to post them.

Try these, they should give you clues to re-writing the problem. If not, try Googling for the rules that govern these types of calculations.

http://www.mathwords.com/s/square_root_rules.htm
http://www.mathwords.com/r/radical_rules.htm
http://www.mathwords.com/e/exponent_rules.htm

E: I think exponent rules should definitely give you the answer and then it's a case of simplifying - or arranging into the solution given.

Multiply by the conjugate is what it is called, just for a reference.

From: HyperSecret
Multiply by the conjugate is what it is called, just for a reference.

Thanks both of you, I read those pages and I understand the problem now.

This program was phenomenal to me when I needed help in algebra many years ago
http://www.bagatrix.com/algebra.aspx
http://www.bagatrix.com/trigonometry.aspx

Might be of use to you :)

I plan on using it for linear algebra and finite math in college
E: Its expensive, so I would … uhh

From: R4nd0m
This program was phenomenal to me when I needed help in algebra many years ago
http://www.bagatrix.com/algebra.aspx
http://www.bagatrix.com/trigonometry.aspx

Might be of use to you :)

I plan on using it for linear algebra and finite math in college
E: Its expensive, so I would … uhh

This could just save me :)

Checking it out as we speak, will edit this post.

I've obtained it, looks awesome!

Just Surds.

(√(7) + √(2)) / (√(7) - √(2))

Simplifies to:

√9 / √5

Simplifies to:

√1.8 (√1 4/5) = √9/5

But it's midnight i'm fucking tired so idk check

Don't you know these equations? :garfield:




(√(7) + √(2)) / (√(7) - √(2)) =

= ( (√(7) + √(2)) * (√(7) + √(2)) ) / ( (√(7) - √(2)) * (√(7) + √(2)) )

= ( 7 + 2 + 2*√(2)*√(7) ) / ( 7 - 2 ) = ( 9 + 2*√(2)*√(7) ) / 5

= ( 9 + 2*√(14) ) / 5

[QUOTE=Camaro';905320]It's my middle of the year exam (Mid Exam, or Mid Term) and I'm taking algebra/trigonometry but I need some help.

For one I'll just post a problem

Which expression is equivalent to (?(7) + ?(2)) / (?(7) - ?(2))

The answer is C but i need to know how to get to that answer without just plugging it into my calculator(plug in all the choices).

A) (11 + ?(2)) / 14
B) 9/5
C) (9 + 2?(14)) / 5
D) - 1

Edit: I understand that problem now, go to my next post for the new one.
Should of just taken a picture but whatever, I'd really appreciate if someone could add my msn [email]aarondawg14@yahoo.com[/email] and give me some more help :)

Could give you something in RS.

9/5
because when we multiply its conjugate then upper part get 9 ans when square rot cancel with square of 7 and as 2. so the sign + make both values 9. and the denominator get 5 because the same procedure we apply but sign - it makes 5.

[QUOTE=Camaro';905320]It's my middle of the year exam (Mid Exam, or Mid Term) and I'm taking algebra/trigonometry but I need some help.

For one I'll just post a problem

Which expression is equivalent to (?(7) + ?(2)) / (?(7) - ?(2))

The answer is C but i need to know how to get to that answer without just plugging it into my calculator(plug in all the choices).

A) (11 + ?(2)) / 14
B) 9/5
C) (9 + 2?(14)) / 5
D) - 1

Edit: I understand that problem now, go to my next post for the new one.
Should of just taken a picture but whatever, I'd really appreciate if someone could add my msn [email]aarondawg14@yahoo.com[/email] and give me some more help :)

Could give you something in RS.

= ( 9 + 2*?(14) ) / 5 just we multiply it conjugate and after applying simple formulas we get this easily

lmfao
took ppl long enough :)
soloution:
Steps- Multiply by conjugate pair to achieve the difference of 2 squares, this cancels out the the surds in the denomuinator, then expand out of the brackets

From: Anguse
9/5
because when we multiply its conjugate then upper part get 9 ans when square rot cancel with square of 7 and as 2. so the sign + make both values 9. and the denominator get 5 because the same procedure we apply but sign - it makes 5.

Major gravedig, try looking at the date of the last post before posting.