We start with
and wish to write it as
First, pull 2 out from the first two terms:
Let’s look at what is in parenthesis. In the final form this needs to be a perfect square. Right now we have
and we can obtain -10x by adding -5x and -5x. That is, we can build the following perfect square:
The “problem” with what we just did is that we added to what was given. Let’s put the expression together. We have
and when we multiply that out it does not give us what we started with. It gives us
So you see our expression is not right. It should have a -53 but instead has a -3. So to correct it we need to subtract another 50.
We do this as follows:
which gives us the final expression we seek:
If you multiply this out you will get the exact expression we were given. This means that:
a = 2
d = -5
e = -103
We are asked for the sum of a, d and e which is 2 + (-5) + (-103) = -106
=(14+3i) - (-12-7i) + (6+2i)
=14 + 3i +12 + 7i + 6 + 2i
=32 + 12i
Using hit and trial, you van find it pretty easily-
- Putting x=0, we get y=-3
- Putting x=1, we get y=-1
- Putting x=2, we get y=5
You can try it for yourself as well, for me, I couldn't find any other option appropriate.