Keegan and jeff did some research and found that there are approximately 7,492,000,000,000,000,000 grains of sand on earth. jeff says that this is about 7x10 to the 15th power grains of sand. keegan says this is about 7x10 to the 18th power grains of sand. a. how might jeff have determined his estimate? how might keegan have determined his estimate?
b. who’s estimate, jeff or keegan’s, is more logical, explain

help me pls :’(

Each of the four sides of a swimming pool measures 9 meters. the pool is 5 meters deep. how much water will be needed to fill it completely? a. 45 cubic meters b. 81 cubic meters c. 225 cubic meters d. 405 cubic meters reset next

Which equation is y = -6x2 + 3x + 2 rewritten in vertex form?

Given the system of equations presented here: 2x + 4y = 14 4x + y = 20 which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated? multiply the second equation by â’4 to get â’16x â’ 4y = â’80 multiply the second equation by â’1 to get â’4x â’ y = â’20 multiply the first equation by 2 to get 4x + 8y = 28 multiply the first equation by â’1 to get â’2x â’ 4y = â’14