algebra- showing how to do it not just the answer?

Question

a is the midpoint of XY (it has a line above the x and y), then it asks:
a. Find xa
b. find ay and xy

Answer 1

xa = xy/2

ay = xy/2

Try substituting a figure for the value xa, say 5. That gives you the value of half of the line xy (i.e. xa = xy/2) Therefore, xy would be 10. As you've already pointed out, 'a' is the midpoint of xy, so ay must also be equal to xa.

Use any number to equal xa and you'll see, quite clearly, that xa = ay.

Answer 2

Your example is geometry.

You are getting bogged down in details. Algebra is just a different language and an equasion is a sentence. For example:

"Never drive so fast that you can't stop in the distance you can see."

There are variables in that equasion. Start at the logical place, which is "how far can you see?". If the answer is 1000 feet, at what speed can you stop in 1000 feet? That speed is a safe speed.