the product of the squares of two positive integers is 1600 . how many pairs of positive integers satisfy this condition ?
"ans : e - 4 pairs ( x ˆ 2 ) ( y ˆ 2 ) = 1600 [ square root both sides ] xy = 40 40 = 1 x 40 , 4 x 10 , 40 x 1 , 10 x 4 , 5 x 8 , 8 x 5 , 20 x 2 , 2 x 20 cancel the repeats this leaves us with exactly 4 options . hence , e"
subtract(add(const_2, const_3), const_2)