x2 + 20x = 10

To solve for x, we can start by rearranging the equation as follows:

x^2 + 20x - 10 = 0

Next, we can use the quadratic formula to solve for x:

x = (-20 ± √(20^2 - 4(1)(-10))) / 2(1)
x = (-20 ± √440) / 2
x = (-20 ± 2√110) / 2
x = -10 ± √110

Therefore, there are two possible solutions: x = -10 + √110 and x = -10 - √110.