Please the statement to describe the example (a+b(d+e)

Which equation represents a proportional relationship that has a constant of proportionality equal to 1/5

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.

The ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry