Question 1 On problem #2, which variable will be the easiest to isolate in order to use substitution?
a: x, in the top equation
b: y, in the top equation
c: x, in the bottom equation
d: y, in the bottom equation
Can someone please help me!! please!

A. 90 degrees b. 45 degrees c. 30 degrees d. 120 degrees

The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. if a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. what is the margin of error of the sample mean? a. 0.086% b. 0.533% c. 1.11% d. 2.22%

Plz asap what is the range of the cluster in the scatter plot a. between 4 and 8 years of experience b. between $40,000 and $60,000 c. between 6 and 12 years of experience d. between $10,000 and $60,000