Question

In: Advanced Math

Write a formal proof to prove the following conjecture to be true or false. If the...

Write a formal proof to prove the following conjecture to be true or false.

If the statement is true, write a formal proof of it. If the statement is false, provide a counterexample and a slightly modified statement that is true and write a formal proof of your new statement.

Conjecture: Let w, x, y, and z be single-digit numbers. The 4-digit number wxyz* is divisible by 9 if and only if 9 divides the sum w + x + y + z.

* I don't mean the product of the of these numbers. I mean a four-digit number like 7,235 where w = 7, x = 2, y = 3, and z = 5 are the digits.

Solutions

Expert Solution

Colby Messinger answered 2 years ago
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