chieftang wrote:rijul007 wrote:NEVER use an info of one statement as an assumption in the other...
If you feel you need to do that... the statement must be insufficient...
I know not to carry an assumption over, but what out the specific case above? If you can solve the equation in (2), then doesn't that solution have to work also for (1) in order to not have a conflict?
Valid or Invalid strategy?
The two statements can NEVER contradict each other.
If x=3 works in statement 2, then x=3 MUST also work in statement 1.
But x=3 might not be the ONLY solution in statement 1, in which case statement 1 will be INSUFFICIENT.
To illustrate:
What is the value of x?
1. x²-x = 6.
2. 5x-3 = 12.
Statement 2 has one solution: x=3.
SUFFICIENT.
If we plug x=3 into statement 1, we get:
3³-3=6.
6=6.
Looks good.
But x=3 is not the ONLY solution in statement 1.
x=-2 also works:
(-2)²-(-2)=6
6=6.
Since x=3 is not the ONLY solution in statement 1, statement 1 is INSUFFICIENT, and the correct answer here is B.
There are times, however, when the solution for one statement can help you to PROVE that the other statement also is sufficient.
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