Bobby bought the following items at the school store: 10 pencils for $0.21 each, 8 pens for $0.45 each, and 2 posters for $0.55 each. How much money did Bobby spend in all? Group of answer choices
$5.70
$1.21
$4.70
$6.80

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?