x²+7x+10 = 0 x²+7x = -10 x+7x+ (7/2)² = (x+7/2)² = ( 7/2)² - 10 when completing the square you have added 49/4 to the left side of the equation,you must also add 49/4 to the right of the equation to balance up = 49/4- 10 = 9/4 x+7/2 = + or -√9/4 = 3/2 x = 3/2-7/2 = - 4/2 = -2 or -3/2 -7/2 = -5
