5/6=1/3+d
What fraction or decimal does d equal?

If f(x)=x^3 and g(x)=2x+7 when g(x)=-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.

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?