2. what is the solution of the system?

7x+5y=19
-7x-2y=-16

a. (2,1)
b. (1,2)
c. (7,5)
d. (-7,-2)

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?

How many times larger is 6 × 10^12 than 2 × 10^7? a. 30,000 b. 3,000 c. 3,000,000 d. 300,000

If log(a) = 1.2 and log(b)= 5.6, what is log(a/b)? a. 4.4b. 6.8c. not enough informationd. -4.4