The operation is defined for all a and b by ab = a + b + ab. If ab

Question

The operation □ is defined for all a and b by a□b = a + b + ab. If a□b = 0 and b ≠ -1, what is a in terms of b?

A.  \frac{b + 1}{b}

B.  \frac{b - 1}{b + 1}

C.  \frac{1}{b + 1}

D.  \frac{b}{b + 1}

E.  -\frac{b}{b + 1}

gmatophobia · Accepted Answer

a□b = a + b + ab

0 = a + b + ab

-b = a(1+b)

a = \frac{-b}{(1+b)}

Option E

Paras96 · Answer

The operation □ is defined for all a and b by a□b = a + b + ab. If a□b = 0 and b ≠ -1, what is a in terms of b?
=>a□b = 0
=>a + b + ab = 0
=>a+ab=-b
=>a(b+1)=-b
=>a=-b/(b+1)

Hence E

JeffTargetTestPrep · Answer

a □ b = 0

a + b + ab = 0

a(1 + b) = -b

Since b ≠ -1, we can divide by 1 + b ≠ 0:

a = -b/(1 + b)

Answer: E

BrushMyQuant · Answer

a□b = a + b + ab. If a□b = 0 and b ≠ -1

=> a + b + ab = 0
=> a + ab = -b
=> a * (1 + b) = -b
=> a =  \frac{-b}{b + 1}

So,  Answer will be E 
Hope it helps!

Watch the following video to learn the Basics of Functions and Custom Characters

https://www.youtube.com/watch?v=b7JoMX0gk8M

Ram26 · Answer

Its a very easy question but I complicated it, I was thinking about b not equal to -1 and wasted my time, which was no use to this question

The operation is defined for all a and b by ab = a + b + ab. If ab

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The operation is defined for all a and b by ab = a + b + ab. If ab

Prep Toolkit

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