Math, asked by Anmol281, 1 year ago

solve 14th sum.........

Attachments:

Answers

Answered by siddhartharao77
2
Here alpha = a and beta = b. Because it is difficult to write alpha and beta always.

Given a and b are roots of x^2 - 6x + k.

We know that sum of the roots = -b/a

                                                     = -(-6)/1

                                                     = 6.

a + b = 6  --------------- (1)


We know that product of roots = c/a

                                                    = k/1

                                                    = k.

ab = k   ----------- (2)


Given that 3a - 2b = 20  ------------ (3)

On solving (1) * 3 & (3), we get

3a + 3b = 18

3a - 2b = 20

------------------

        5b = -2

          b = -2/5.


Substitute b = -2/5 in (1), we get

a + b = 6

a - 2/5 = 6

a = 6 + 2/5

a = 32/5.


Substitute a and b in (2), we get

ab = k

32/5 * -2/5 = k

-64/25 = k


Therefore the value of k = -64/25.


Hope this helps!  -------------- Good Luck.

siddhartharao77: If possible brainliest it
Anmol281: thanxx.answer is -16
siddhartharao77: If the question is 3alpha + 2beta=20 then the answer will be -16.
Anmol281: ok
TANU81: Nice
Answered by Anonymous
1
alpha

 = a and beta = b 

                  ----------     a and b are roots of x^2 - 6x + k.  -----------------




********************** sum of the roots = -b/a   *************************

                                                     = -(-6)/1

                                                     = 6.

a + b = 6           ____________  ( 1 ) 

                             

                                                                product of roots = c/a

                                                    = k/1

                                                    = k.

                                              ab = k   ----------- (2)









----------------------     3a - 2b = 20  ------------ (3)





(1) * 3 & (3), we get

3a + 3b = 18

3a - 2b = 20

------------------

        5b = -2

          b = -2/5.


Substitute b = -2/5 in (1), 

a + b = 6

a - 2/5 = 6

a = 6 + 2/5

a = 32/5.


Substitute a and b in (2), we get

ab = k

32/5 * -2/5 = k

-64/25 = k


Therefore the value of k = -64/25.

Similar questions