Let's take the number as x.
two-fifths of a number = 2x / 5
decreased by 3 = (2x/5) - 3
(2x/5) - 3
(2*25/5) - 3
(2*5) - 3
10 - 3
7
Answer:
no! you can label either of the legs a or b. it doesn't matter. the hypotenuse always stays as c though if you're using a formula.
