Question 1145843
Dale = n
Rosa = n - 8
<pr>
n(n - 8) = 105
<pr>
n² - 8n = 105
<pr>
n² - 8n - 105 = 0
<pr>
(n + 7)(n - 15) = 0
<pr>
n = -7, 15.  Since n = -7 would make Dale's age (n) a negative number, we can eliminate this result.  Therefore, we are left with n = 15.
<pr>
Dale = n = <b>15</b>
Rosa = n - 8 = 15 - 8 = <b>7</b>