Three rays have a common vertex on a line. Write and solve equations to find the measures of m and n

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

The price of a visit to the dentist is \$50$50. if the dentist fills any cavities, an additional charge of \$100$100 per cavity gets added to the bill. if the dentist finds nn cavities, what will the cost of the visit be?

In the triangle rst, rs = 65 and st = 60. which equation could be used to find the value of angle s?