Question

If px²+3x+q=0 has two roots -1 and -2, then the value of q - p is

Answer 1

Step-by-step explanation:

x=-1

px²+3x+q=0

p(-1)²+3(-1)+q=0

p-3+q=0

p+q=3

p=3-q -------1.

x=-2

px²+3x+q=0

p(-2)²+3(-2)+q=0

4p-6+q=0

Put the value of p from eq1

4(3-q)-6+q=0

12-4q-6+q=0

6-3q=0

-3q=-6

q=-6/-3

q=2. put in eq1.

p=3-q

p=3-2

p=1