Math Question

Question

I can't quite figure out how to solve for a in terms of b for this question:

(a^2)/(b^2) + (2a/b) = -1

Any help explaining this would be great!

tkarthi4u · Answer

hi,

(a^2)/(b^2) + (2a/b) = -1

take the lcm then (a^2 + 2ab)/b^2 = -1

a^2+2ab = -b ^2

(a+b)^2 = 0 or a+b = 0 so a =-b.

please correct me if i am wrong.

trojansc82 · Answer

That looks right. Unfortunately it was part of a practice test and I didn't finish it, so I can't go back and check the answers. I'm assuming this is the technique used...thanks a lot for your help!

ThePower · Answer

we can replace t=a/b:
t^2+2t=-1 
so:
t^2+2t+1=0
(t+1)^2=0
t=-1 -> a/b=-1 -> a=-b

firasath · Answer

you need to memorize these equations of binomials:

(a+b)(a+b) = a^2 + 2ab + b^2
(a-b)(a-b) = a^2 - 2ab + b^2
(a+b)(a-b) = a^2 - b^2

be able to convert them forwards and backwards. Knowing this will enable you to solve this very quickly.

tarun · Answer

This question was in which practice test?

sidhu4u · Answer

a^2/b^2+2a/b = -1

(a^2+2ab)/b^2 = -1
a^2+2ab = -b^2
a^2+2ab+b^2 = 0
so (a+b)^2=0
a+b = 0
or a = -b

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