Solve using substitution:
2x - 3y = -1
y = x - 1

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?

Billie holiday sells children's clothing for sara vaughn's toddler shop. baby blankets sell for $29.99 after a markup rate based on cost of 109%. find the cost and the markup.

Which expression is equal to (f+g)(x)?