Answer:
d=3 and e=-1
Step-by-step explanation:
d+e=2
d=2-e-----(1)
d-e=4-----(2)
substituting (1) in (2)
2-e-e=4
-2e=2
e=-1-----(3)
substituting (3) in (1)
d=2-(-1)
d=3
Answer:
5 , -7 , 10
Step-by-step explanation:

There are 2 roots so the only way to complete the square is,
![y=2x^2+8x-9\\y=2[(x^2+4x)]-9\\y=2[(x^2+4x+4)-4]-9\\y=2[(x+2)^2-4]-9\\y=2(x+2)^2-8-9\\y=2(x+2)^2-17](https://tex.z-dn.net/?f=y%3D2x%5E2%2B8x-9%5C%5Cy%3D2%5B%28x%5E2%2B4x%29%5D-9%5C%5Cy%3D2%5B%28x%5E2%2B4x%2B4%29-4%5D-9%5C%5Cy%3D2%5B%28x%2B2%29%5E2-4%5D-9%5C%5Cy%3D2%28x%2B2%29%5E2-8-9%5C%5Cy%3D2%28x%2B2%29%5E2-17)
Just factor 2 out of 2x^2+8x (just ignore the -9) then find the number that will make the terms be able to complete the square.
then complete the square and multiply 2 inside the brackets.
subtraction as you already get the vertex form and know how to complete the square.
Vertex Form: 
We have to solve x in terms of a, b and c:
a x - 3 b = c
a x - 3 b + 3 b = c + 3 b
a x = c + 3 b
x = ( c + 3 b ) : a
Answer:
4 ) ( c + 3 b ) / a
1,134. :DD Hope I helped!