Solve the equation by completing the square root round to the nearest hundredth if necessary x^2+3x=24

X^2 + 3x = 24

completing the square
(x + 1.5)^2 - 2.25 = 24

(x + 1.5)^2 = 26.25

x + 1.5  = +/- sqrt26.25 =  +- 5.123

x = -1.5 + 5.123 = 3.62 to nearest hundredth  and

x =  -1.5 - 5.123  =   -6.62 to nearest hundredth

solution set is {-6.62, 3.62}

Remember the formula (b/2)^2. The 3 is b, so (3/2)^2, which is 2.25. x^2+3x+2.25=26.25 

Figure it out your self