Robert tutors two students, Andy and Susie. Andy pays Robert $70 per month. Susie pays Robert $50 per month. How many months will Robert have to tutor before he earns $600?

Find the greatest common factor of -30x 4 yz 3 and 75x 4 z 2.

Find the perimeter of the triangle with vertices  d(3, 4),  e(8, 7), and  f(5, 9). do not round before calculating the perimeter. after calculating the perimeter, round your answer to the nearest tenth.  

The price of a visit to the dentist is calculated according to the formula 50+100n50+100n where nn is the number of cavities the dentist finds. on your last visit to the dentist, 22 cavities were found. what was the cost of your visit?