Question

Find value of p so that quadratic equation px(x-3)+9=0 has two equal roots

Answer 1

First open the bracket
px^2 -3px+9=0

Condition for equal roots: b^2 - 4ac=0
9p^2- 36p=0
p^2-4p=0
p(p-4)=0
p=0 p=4

Answer 2

b²-4ac  =o
9p²-4p×9 =0
9p²-36p=0
9p[p-4] =0
p=4