prove b is odd integer if and only if b^2+7 is even
Added by Marie C.
Step 1
Assume b is odd. Then we can write b as 2k+1, where k is an integer. Now, we can substitute this expression for b into b^2+7: b^2+7 = (2k+1)^2 + 7 = 4k^2 + 4k + 1 + 7 = 4k^2 + 4k + 8 = 4(k^2 + k + 2) Since k^2 + k + 2 is an integer, we Show more…
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