-2.5x - 10 = 40 what is the missing variable

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.

An investment decreases in value by 30% in the first year and decreases by 40% in the second year. what is the percent decrease in percentage in the investment after two years

Which statement accurately describes how to perform a 90° clockwise rotation of point a (1,4) around the origin?