His error was that he did not flip the inequality sign.
31<5x+6
25<-5x
-5>x
You don't have all the numbers, you don't know what X equals, you need to know what X equals in order to complete the equation
Answer: division property of equality
Step-by-step explanation:
8x = 80
You divide the number with the letter you are trying to find (x) on both sides, so 8 divided by 80, you get 10.
Answer: The 3 in 3,899 is 10 times the 3 in 4,385!