What is the equation of the horizontal line through (-4, 6)

In a school 2/3 of the students study a language of those who study a language 2/5 study french

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.

Need plz been trying to do it for a long time and still haven’t succeeded