Teniendo en cuenta la propiedad fundamental de las proporciones, comprueba si las siguientes son o no proporciones a) 5/7 = 15/21 b) 20/7 = 5/3 c) 16/8 = 4/2

How many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

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?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.