Hi
[email protected],
Brent's approach focused on the algebra that you could do to get to the correct answer. There is another way to approach this question though....we can TEST THE ANSWERS
The answer choices provide us with 5 possibilities for what MIGHT be the solutions to the above equation (make the above equation = 0). We just have to figure out which one actually does it.
First off, notice that Z = 3 is in most of the options. Let's see what happens when we TEST Z = 3
(Y - 1)(3 - 3) + 5(3 - 3) =
(Y - 1)(0) + 5(0)
0 + 0 = 0
So, if Z = 3, then the above equation DOES equal 0 (and the value of Y DOESN'T MATTER). This tells us 2 things:
1) Z = 3 is one of the solutions
2) The Y doesn't matter in this scenario (so we don't need an "and", we need an "or" in the correct answer)
Eliminate A, B and D
Between answers C and E, the difference is in the values of Y (-4 or + 1). I'm going to TEST the easier option. What happens when Y = 1....?
(1 - 1)(Z - 3) + 5(Z - 3)
(0)(Z - 3) + 5(Z - 3)
0 + 5(Z - 3)
This would only equal 0 when Z = 3, but it would NOT equal 0 under any other circumstances. This CANNOT be the answer.
Eliminate E
Final Answer:
C
GMAT assassins aren't born, they're made,
Rich
