Identify a set of parallel lines and a set of perpendicular lines in this image. Please help

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

We just started the introduction into circles and i have no idea how to do this.

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10