Jean is planning to take a foreign-language class. to research how satisfied other students are with their foreign language classes, she decides to take a sample of 50 such students. the university offers classes in five languages: spanish, german, russian, french, and japanese. she will select a random sample of 10 students from each language. what best describes the sampling technique jean is using?
a) a simple random sample
b) a stratified random sample
c) a voluntary response sample

As part of an annual fundraiser to raise money for diabetes research, diane joined a bikeathon. the track she biked on was 1,920 yards long. diane biked 38.5 laps. her sponsors agreed to donate an amount of money for each mile she biked. how many miles did she bike? first fill in the blanks on the left side using the ratios shown. then write your answer. given ratios: 5280ft / 1 mi , 1 mi /5280 ft , 1,920 yards / 1 lap , 1 lap / 1,920 yards , 3 ft / 1 yard , 1 yard / 3 ft. blanks: 38.5 laps / 1 yard x (blank) x (blank) x (blank) = (blank) miles i'm really confused on how to do this, and the explanations aren't exactly . if you could walk me through how to do this, it would be greatly appreciated.

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

Valentina is subtracting from . she finds the lcd to be 15y2. what is valentina's next step?