Can someone explain the concept of algebra? just give me some basic tips so i can solve questions like the ones in the picture. in advance!

Algebra basically consists of mathematical operations, but using letters. To solve the exercises you only have to say that is the variable X

for Example: 4x= 8
                       x= 8 divide by 4
                       x= 2

In particular to the equations above, your goal is to find the value of x.

Step 1: isolate the variable (in this case,x).
Isolating the variable makes you narrow down what you are solving for.

Step 2: solve for the variable.
You can solve for the variable by making x alone (meaning with no coefficient).

If you have any questions on how you can do these while it still being mathematically legal, let me know and I will help.

Skew lines(segments) are lines(segments) in 3 dimensions that do not intersect the given segment and are not parallel to it.  ae, bf, eg, and fh are your skew segments.  i hope that : )