zisis wrote:
If a=1 and (a-b)/c = 1 which of the following is NOT a possible value of b?
A. -2
B. -1
C. 0
D. 1
E. 2
If a = 1, we have:
(1 - b)/c = 1
1 - b = c
We must also remember that since (1 - b)/c = 1, and since dividing by zero creates an undefined result, c cannot be zero.
Let’s test the answer choices:
A) -2
Since c = 1 - (-2) = 3, b could be -2.
B) -1
Since c = 1 - (-1) = 2, b could be -1.
C) 0
Since c = 1 - 0 = 1, b could be 0.
D) 1
Since c = 1 - 1 = 0, b cannot be 1.
Alternate Solution:
If a = 1, we have:
(1 - b)/c = 1
1 - b = c
The original equation had c in the denominator, so we know that c cannot equal 0. The value of b that makes c = 0 is b = 1. Thus, b cannot equal 1.
Answer: D
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