Solve the system of equations 2.5y+3x=27 5x-2.5y=5 what equation is the result of adding the two equations

Cora bought a package of erasers. there are 4 pink erasers and 12 blue erasers. what is the ratio of pink erasers to blue erasers?

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76