Completing the square

Jklol:

Solve equation by completing the square
2d^2=8+10d

The first thing that i notice is that I can divide everything by 2. so do that, it will make it easier.
d ²=4+5d
Now it is best to have all the ds on one side and the number by itself on the other side.
so subtract 5d from both sides
d ²-5d=4
Now
x ² + bx + (b/2) ² = (x+a) ²
The x is the same as your d
Your b = -5
So the last term must be (-5/2) ² = 25/4
So you need to add 25/4 to both sides.
d ²-5d=4
d ²-5d+(25/4)=4+(25/4)
(d-(5/2)) ²=(16+25)/4
(d-(5/2)) ²= (41)/4
so
d - 5/2 = +- sqrt(41/4)
d= 5/2 +- [sqrt(41)]/2

d = [5 +- sqrt(41)] / 2