Jeremy's teacher buys 6 packs of thumbtacks. Each pack contains t thumbtacks. She uses 18 thumbtacks to display posters around her classroom. Which expression gives the number of
thumbtacks she has left?
A) 3(6-t)
B) 3(t-6)
C) 6(t-3)
D) 6(3-t)

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?

Is triangle jkl congruent to triangle rst? if so, what is the scale factor?

Agroup of student volunteers participates in a study designed to assess several behavioral interventions for improving output in a repetitive task. prior to the beginning of the study, all volunteers unknowingly observed, and their output is measured. at the beginning of the study, prior to any intervention, the volunteers perform the same task under the observation of a study administrator, and their overall output increases. which of the following terms describes this phenomenon? a. simpson's paradox b. hawthorne effect are d. novelty effect d. pygmalion effect e. observer-expectancy effect