Posted by Mary on Monday, February 13, 2012 at 5:27pm.
Please show me how to set and solve:
The sum of two numbers is 90. Their difference is 12. What are the numbers?

Math  Steve, Monday, February 13, 2012 at 6:06pm
x + (x12) = 90
2x = 102
x = 51
the two numbers are 39 and 51