Why is the product of two rational numbers always rational? select from the drop-down menus to correctly complete the proof?

Getting the product of two rationals is like multiplying two fractions, which will have another fraction of this alike form as the result because integers are sealed under multiplication. All rational number can be signified as q/r, with q and r are both integers. Another explanation is the product of two rational numbers is q/r * s/t, with q, r, s, and t are integers. Nonetheless, this is just (qs)/(rt), and qs and rt are both results of integers and hence integers themselves. The product of two rational numbers can be characterized as the quotient of two integers and is itself rational. Therefore, multiplying two rational numbers yields another rational number.

-8/2y-8=5/y+4-7y+8/y^2-16

we move all terms to the left:

-8/2y-8-(5/y+4-7y+8/y^2-16)=0

we can not solve this equation