Answer:
The number to be added is 81/4
Step-by-step explanation:
To get the number, we look at the coefficient of x
In this case, we have it as -9
we divide this by 2
It gives (-9/2)
We square this value and add it to both sides
This would be
(-9/2)^2 = 81/4
It is this number we will add to both sides of the equation