Answer:
option b is the answer of your question
To complete the square you halve the coefficient of the x term and square it. Half of 14 is 7 and 7² is 49. So we add 49 and subtract 49, which means we are not changing the value of the quadratic. So we have x²+14x+49-49+2. This can be written: (x²+14x+49)-49+2, which is (x+7)²-47, which is answer a.
As a engineer who was mechanical then electrical most buildings, schematics,etc require some form of calculation for some shapes seeing that those shapes are what make up the world. Say for example you need to make something like a mother board pro house knowing it's shape and angle helps make a more accurate structure during the blue printing and build phase. No one just goes in and wings it you need to determine angles for things you don't know that the point of it.