Question

27. Prove
28.If-5 is a root of a quadratic equation 2x2+ px- 15= 0 find the value of p
and the other root of the equation.​

Answer 1

Step-by-step explanation:

Since −5 is a root of the equation 2x

2

+px−15=0. Therefore,

2(−5)

2

−5p−15=0⇒p=7

Putting p=7 in p(x

2

+x)+k=0 we get

7x

2

+7x+k=0

Here ,a=7,b=7;c=k

This equation will have equal roots, if

Discriminant =b

2

−4ac=0 ⇒49−4×7×k=0⇒k=

28

49

⇒k=

4

7

Answer 2

Answer:

x= -5

p=?

Step-by-step explanation:

2x²-px-15=0

put x= -5

2(-5)²-p(-5)-15=0

50+5p-15=0

35+5p=0

5p= -35

p= -35/5

therefore,

p= -7

I hope this will help you...

All the best for algebra