Answer:
p = 

Explanation:
let the root be α then the other root is 3α
The sum of the roots of a quadratic equation is
α + 3α = - 
 = -
 = - 
 =
 = 

Thus 4α = 
 ( divide both sides by 4 )
 ( divide both sides by 4 )
α = 

The product of the roots of a quadratic equation are
α × 3α = 
 =
 = 
 , that is
, that is
3α² = 
 ← substitute value of α
 ← substitute value of α
3 × (
 )² =
 )² = 

3 × 
 =
 = 

 =
 = 
 ( cross- multiply )
 ( cross- multiply )
49p = 84 ( divide both sides by 49 )
p = 
 =
 = 
