X=?
1.a^(2x)=b^(x+6)
2.ab=1
It seems that I should choose C for this one as when you combine these two statements, you will get x=-2. Since a and b are different letters, I assume they represent different numbers. I am just wondering if I need to consider a=b=1, cuz that will change the answer to E..
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The problem does not indicate a and b must be distinct values.allenh wrote:X=?
1.a^(2x)=b^(x+6)
2.ab=1
It seems that I should choose C for this one as when you combine these two statements, you will get x=-2. Since a and b are different letters, I assume they represent different numbers. I am just wondering if I need to consider a=b=1, cuz that will change the answer to E..
Thus, when the statements are combined, it is possible that a=b=1.
Statements combined:
Plugging a=b=1 into a^(2x) = b^(x+6), we get:
1^(2x) = 1^(x+6).
In this case, x can be ANY VALUE.
Since the value of x cannot be determined, the two statements combined are INSUFFICIENT.
The correct answer is E.
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When it comes to exponent questions with several variables, it's useful to consider what happens when the bases are 0 or 1 and what happens when the variables are 0 or 1.
In this case, we can see that, if a and b both equal 1, the equation a^(2x)=b^(x+6) is true for ANY VALUE of x.
Cheers,
Brent
In this case, we can see that, if a and b both equal 1, the equation a^(2x)=b^(x+6) is true for ANY VALUE of x.
Cheers,
Brent
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Max@Math Revolution
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X=?
1.a^(2x)=b^(x+6)
2.ab=1
In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem.
Remember equal number of variables and equations ensures a solution.
vatiables'number:3 --> needs 3 equations --> E
1) & 2)
if a=b=1, it is possble that 2x is not equal to x+1, therefore the answer is E
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1.a^(2x)=b^(x+6)
2.ab=1
In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem.
Remember equal number of variables and equations ensures a solution.
vatiables'number:3 --> needs 3 equations --> E
1) & 2)
if a=b=1, it is possble that 2x is not equal to x+1, therefore the answer is E
www.mathrevolution.com
- The one-and-only World's First Variable Approach for DS and IVY Approach for PS that allow anyone to easily solve GMAT math questions.
- The easy-to-use solutions. Math skills are totally irrelevant. Forget conventional ways of solving math questions.
- The most effective time management for GMAT math to date allowing you to solve 37 questions with 10 minutes to spare
- Hitting a score of 45 is very easy and points and 49-51 is also doable.
- Unlimited Access to over 120 free video lessons at https://www.mathrevolution.com/gmat/lesson
- Our advertising video at https://www.youtube.com/watch?v=R_Fki3_2vO8
