Jackie found a rock that has a mass of 78.852 grams. what is the mass of the rock rounded to the nearest tenth?

78.852 = 78.9 <=== nearest tenth

The nearest tenth would be the number immediately after the decimal point. So it would be 78.8 then you would look to the number to the right of the 8, and it is a 5 so the eight rounds up to nine. Therefore 78.852 grams rounded to the nearest tenth is 78.9 grams.

e) none of the above because the measure of angle cba is 101°

the solution is 12x-6y