Answer:
-13, -3
15, 2.6
Explanation:
x, y are the numbers
x = 5y + 2
x×y = 39
(5y + 2)×y = 39
5y² + 2y - 39 = 0
the solution of a quadratic equation :
y = (-b ± sqrt(b² - 4ac))/2a
a = 5
b = 2
c = -39
y = (-2 ± sqrt(2² - 4×5×-39))/2×5 =
= (-2 ± sqrt(4 + 780))/10 =
= (-2 ± sqrt(784))/10 = (-2 ± 28)/10
y1 = (-2 + 28)/10 = 26/10 = 2.6
y2 = (-2 - 28)/10 = -30/10 = -3
x1 = 5×2.6 + 2 = 13 + 2 = 15
x2 = 5×-3 + 2 = -15 + 2 = -13