Which equation could be represented by the number line? O A. -6+ 5 = -1 B. 1 + (-6) = -5 C. -5 + 6 = 1 O D. 1+(-7) = -6 PLS HELPP MEE OUT

In trapezoid abcd, ac is a diagonal and ∠abc≅∠acd. find ac if the lengths of the bases bc and ad are 12m and 27m respectively.

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

Find the exact value of cos(arcsin( one fourth for full credit, explain your reasoning. (2 points)