What number should be added to both sides of the equation to complete the square?

x2 + 3x = 6

3/2

(3/2)^2

3

6^2

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225

4 and 5)16.97 or 12√2

6)15.59 or 9√3

7)y = 15.59 or 9√3     x =27

8)17.80

answer: 8

step-by-step explanation: if you add the possibilities 5 different flavor and 3 different sizes 5+3=8