(I'm going to use brackets as my absolute value bars lol)
[5 x -3]
[-15]
=15
You need to win 30 matches in a row to raise its winning percentage to 90%
The answer for that is .. 17?
Answer: ![(-\infty, -4]](https://tex.z-dn.net/?f=%28-%5Cinfty%2C%20-4%5D)
Curved parenthesis at negative infinity
Square bracket at -4
====================================================
Work Shown:

The last inequality shown above is the same as saying 
Converting this to interval notation leads to the final answer of ![(-\infty , -4]](https://tex.z-dn.net/?f=%28-%5Cinfty%20%2C%20-4%5D)
Note the use of a square bracket at -4 to include this endpoint. We can never include either infinity, so we always use a parenthesis for either infinity.
difference= 0.78[Anastasia's] - (1 - 0.34)[Sergei's]=
0.78m - (0.66m)=0.12m=12cm