Square of the units digit. Find the number.

You ned to set this problemn up as two equations in two unknowns. Let's call the tens digit 'A', and the units digit 'B'. You know that:

A + B = 9 (since the sum of the tens digit and units digit is 9)
A = B^2-3 (since the tenbs digit is 3 less than the square of the units digit)

Yo can now rearrange the first equation to get A by utself, then substitute that equation for A into the second equation. At this point you'll have one equation for B, which will be a quadratic that you can factor to determine B. Then finally substitute that value for B back into the first equation to figure out what A is. Good luck, and post back with what you get for a final answer.