Posted by mark on .
When seven times a number is added to the square of the number the result is 18. Find the number.

Math 
DrBob222,
Let X = the number.
7X + X^2 = 18
Rearrange to
X^2 + 7X 18 = 0
Solve for X.
You will get two answers, one positive and one negative. Both will satisfy the equation.