Let x be the number. We have: x^2 + x = 30 Subtract 30 from each side: x^2 + x - 30 = 0 Using our quadratic calculator, we get potential solutions of: x = 5 or x = -6 Check 5: 5 + 5^2 = 5 + 25 = 30 Check -6 -6 + -6^2 = -6 + 36 = 30