I did not even read this because im too very lazy but it is prolly easy so can you help me please its due today Which of the following is true about this mathematical statement: 2x + 9 = 7 + x ?
A. It is an equation because it has an equal sign.
B. It is an equation because it has the variable x.
C. It is an expression because it has an equal sign.
D. This is an equation because it has a mathematical operation sign.

Aman is 6 feet 3 inches tall. the top of his shadow touches a fire hydrant that is 13 feet 6 inches away. what is the angle of elevation from the base of the fire hydrant to the top of the man's head?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

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.