Directions: Use the digits 1 to 9, at most one time each, to create an equation where x has the greatest possible value.

### Hint

How does the value of the number being added to x affect the value of x?

How does the value of the sum affect the value of x?

How can we tell whether it is better for the two missing numbers to have a larger or smaller value?

How does the value of the sum affect the value of x?

How can we tell whether it is better for the two missing numbers to have a larger or smaller value?

### Answer

The equation 12 + x = 98 results in x having a value of 86.

Source: Robert Kaplinsky

If you would like the value of x to be included in the “no repeated numbers”, the equation would be 12 + x = 97 and x = 85

Ooh. Neat modification.

Talking with some colleagues, we are thinking that this problem may fall better under 6.EE.6. Good problem either way.

X cannot be greater than 9 right? If so than:

1 x 3 + x = 2 x 6

3 + x = 12

x = 9

9 is the biggest possible number.