What is 1/3 - 3/7 i really need with this problem. i'm just a 3rd

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

Find the quotient. 50a2 – 98b2 -5a +7b

Jalen charges $25.50 for every 3 hours of yard work he does for his neighbors. ralph charges $34 for every 4 hours of work that he does. who charges less? opinions: 1.they charge the same amount 2.jalen 3.ralph