stacy multiplied 5x9 and said the answer was 44. what two patterns could you use to show that her answer is not correct?

The digits of any number multiplied by 9 add up to 9

Example:
8 * 9 = 72
7 + 2 = 9

The last digit of the product of 5 and any other number always ends in 5 or 0.

Examples:
5 * 3 = 15
5 * 4 = 20