What's the difference of 9(2k-4) and -2(7k-12)

Iwill give ! if m∠a=59 and m∠3=81°, what is m∠b? m∠b= _[blank]_°

1- is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis. 2- 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. 3- 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 part b?

Which statement is true? n is a point of tangency on circle p. pt is a secant of circle p. is a secant of circle p. vu is a tangent of circle p.