Angle measurements in degrees

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.

Which of the points a(6, 2), b(0, 0), c(3, 2), d(−12, 8), e(−12, −8) belong to the graph of direct variation y= 2/3 x?

Evaluate the expression for the given value of the variable. | ? 4 b ? 8 | + ? ? ? 1 ? b 2 ? ? + 2 b 3 -4b-8+-1-b2+2b3 ; b = ? 2 b=-2