If the roots of 3x^2-5kx+75=0 are positive and equal,then the roots are?

if two roots are positive and equal, then

the discriminant is equal to zero...

b² - 4ac = 0

where a= 3, b = -5k ,,c = 75

from 3x^2-5kx+75=0.........

b² - 4ac = 0

(-5k)² - 4(3*75) = 0

25k² - 900 = 0

25k²= 900

k ²= 900/25

k=±6

taking positive value

when k is 6

3x² - (5*6)x + 75 = 0

3x² - 30x + 75 =0 ---------- the new equation

x² -10x + 25 = 0

(x - 5 )² = 0

x = 5

the roots are { 5, 5}

let roots be "y" and "y"

Now, we know that the product of the roots = (c/a)

Therefore y x y = (75/3)

y^2 = 25 ---> y=5 (we are told they are positive.)

It has a double root at 5.