Which expression is equivalent to the given expression? (1/7x+6)-(4/7x+3)

The sum of two numbers is 86, and their difference is 20. find the two numbers

Consider the function represented by the equation 1/2 j + 1/4 k equals 3 which shows the equation written in function notation with j as the independent variable

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?