Find the surface area

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is

The vet charges $45 for an office visit and $10 for each vaccination your dog needs. write an eaquation

Find the solution(s) to the system of equations. select all that apply y=x^2-1 y=2x-2