In the equation $$x^2−bx+c=0$$, b and c are constants. What is the value of b ?
(1) -3 is a root of the equation $$x^2−bx+c=0.$$
(2) x + 3 is a factor of $$x^2−bx+c=0.$$
The OA is E.
I don't know how to prove that E is the solution. Experts, may you help me?
In the equation x^2−bx+c=0, . . .
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Hi M7MBA,
We're given the equation X^2 - B(X) + C=0 and we're told that B and C are constants. We're asked for the value of B.
1) -3 is a root of the equation X^2 - B(X) + C=0
Fact 1 gives us one of the solutions to the equation (X= -3), but until we have the other solution, there's no way to determine the values of B or C.
Fact 1 is INSUFFICIENT.
2) x + 3 is a factor of X^2 - B(X) + C=0
Fact 2 gives us one of the factors of the equation (which proves that one of the solutions to the equation is -3), but until we have the other solution, there's no way to determine the values of B or C.
Fact 2 is INSUFFICIENT.
Combined, Fact 1 and Fact 2 tell us the SAME thing (one of the solutions is -3), but we still don't have the other solution, so there's no way to determine the values of B or C.
Combined, INSUFFICIENT.
Final Answer: E
GMAT assassins aren't born, they're made,
Rich
We're given the equation X^2 - B(X) + C=0 and we're told that B and C are constants. We're asked for the value of B.
1) -3 is a root of the equation X^2 - B(X) + C=0
Fact 1 gives us one of the solutions to the equation (X= -3), but until we have the other solution, there's no way to determine the values of B or C.
Fact 1 is INSUFFICIENT.
2) x + 3 is a factor of X^2 - B(X) + C=0
Fact 2 gives us one of the factors of the equation (which proves that one of the solutions to the equation is -3), but until we have the other solution, there's no way to determine the values of B or C.
Fact 2 is INSUFFICIENT.
Combined, Fact 1 and Fact 2 tell us the SAME thing (one of the solutions is -3), but we still don't have the other solution, so there's no way to determine the values of B or C.
Combined, INSUFFICIENT.
Final Answer: E
GMAT assassins aren't born, they're made,
Rich