Explanation:
To solve x^2+10x=15, we can complete the square by adding (10/2)^2=25 to both sides, resulting in (x+5)^2=40. Then, we can take the square root of both sides and solve for x, giving us x=-5±2√10. Alternatively, we can factor the quadratic as (x+5-2√10)(x+5+2√10)=0 and solve for x.