Given equations a and b as 2/5x+y=12 and 5/2y-x=6, respectively, which expression will eliminate variable x?
a.)5/2a+2/5b
b.)5/2a-b
c.)a+2/5b
d.)5/2a-2/5b
e.)25/10a+6/10b

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.

Your company withheld $4,463 from your paycheck for taxes. you received a $713 tax refund. select the best answer round to the nearest 100 to estimate how much you paid in taxes.