3. 4. Let a and b be integers. Show that if @ and b are even, then a + b is even. Definition: An integer is odd if it can be written as 2k + 1 for some integer k. Determine whether the following statement is true. If it is, show that it is true. If not, show that it is false. Statement: Let a and b be integers. If a is odd, then a + b is odd. . Identify at least three mathematical writing errors in the following response to the prompt. For each of these errors, write a sentence indicating what the error is and how it could be corrected. Prompt: Show that the sum of two positive real numbers is positive. Response: a, b positive a=1b=2 1+2 3 a and b are numbers > 0, so when taking the sum of them you get a number that is also > 0, e.g. positive