Can someone please walk me through the work on statement 1. Thanks
If b is an even integer, is b<0?
1. b^2-4b+4<16
2. b^2>9
OA = A
If b is an even integer, is b<0?
1. b^2-4b+4<16
2. b^2>9
OA = A
From Statement 1:tonebeeze wrote:Can someone please walk me through the work on statement 1. Thanks
If b is an even integer, is b<0?
1. b^2-4b+4<16
2. b^2>9
OA = A
b^2 - 4b + 4 < 16
b^2 - 4b - 12 < 0
(b - 6)(b + 2) < 0
We now have a product which is negative. So one factor must be negative, the other positive. Since b-6 is certainly smaller than b+2, it must be that b-6 is the negative factor, and b+2 is the positive factor. So b-6 < 0, and b < 6, and b+2 > 0, so b > -2. Combining these we know -2 < b < 6. Since b must be an even integer, b can only be 0, 2 or 4. So it is certainly *not* true that b<0, and we have a definite answer to the question, so Statement 1 is sufficient.
Statement 2 is not sufficient; b^2 > 9 is true whenever b > 3 or b < -3.
