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Solve for x where 0 equation: cot^2x+2cotx+1=0

During the election for class president, 40% of the students voted for kellen, and 60% of the students voted for robbie. 500 students voted in total. how many more students voted for robbie than for kellen? answer with work : )

Which of the following values have 3 significant figures? check all that apply. a. 10.1 b. 100.05 c. 120 d. 129