How can I factor this trinomial step by step with different methods 15a^2-5a+5

What is another way to express 36 +32

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.

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply