Question

two numbers are in the ratio 4:5the difference of their square is 81, find the numbers​

Answer 1

x/y = 4/5

y^2 - x^2 = 81

x = 4y/5

y^2 - (4y/5)^2 = 81

y^2 - 16y^2/25 = 81

9y^2/25 = 81

y = sqrt (81*25/9)

y = 15

x = 4(15)/5 = 12

Answer 2

Answer:

$(25 {k}^{2} - 16 {k}^{2} ) = 81 \\ {k}^{2} = 9 \\ k = + 3 \\ k = - 3 \\ the \: number \: \\ \: will \: be \: (- 12 \:and \: - 15) \\ and \: (12 \: and \: 15)$