What is 6,418 in scientific notation

Planning for the possibility that your home might get struck by lighting and catch on fire is part of a plan for ?

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.

What is the distance from zero if a quadratic function has a line of symmetry at x=-3 and a zero at 4