Question

x^2+px+q=0, where p and q are constants, has roots -3 and 5.
find the values of p and q

Answer 1

Answer:

LOOK STEP BY STEP EXPLANATION BELOW

Step-by-step explanation:

Given: root_1 = -3 and root_2 = 5 we can write the quadratic as

(x - root_1) * (x - root_2)

= (x + 3) * (x  - 5)

expanding we get

(x + 3) * (x  - 5) = x^2 -5x + 3x - 15

= x^2 -2x - 15

This is the desired quadratic and so

p = -2 and q = -15

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Alternative method

sum of roots = -b/a

product of roots = ca

using the sum of roots formula

5 + -3 = -b/a

2 =- b/a

since a = 1

b = -2

using the product of roots formula

5 * -3 = ca

-15 = ca

since a = 1

c = -15

Answer 2

Answer:

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