In x+3(x+4)=20 you distribute the 3 to the x and 4 but what happens to that 3 afterwards

Need solving this second acceleration problem.

Find the value of x for which the lines are parallel.

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?