Question

19. If x=-2 and x=-3 are roots of quadratic equation ax2 +7x+b=0. Find a and b. 3​

Answer 1

Answer:

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Step-by-step explanation:

The given equation is ax2 + 7x + b = 0. Its roots are given as x 1 = − 3 and x 2 = 2 3 . Thus, the values of a and b are 3 and −6, respectively.

Answer 2

a = 7/5

b = 42/5

Step-by-step explanation:

QUESTION :-

If x = -2 and x = -3 are roots of quadratic equation ax² + 7x + b = 0. Find a and b.

_______________________

SOLUTION :-

ax² + 7x + b = 0

x = -2 and x = -3

by putting the value of x as (-2), we get,

a(-2)² + 7(-2) + b = 0

=> a(4) - 14 + b = 0

=> 4a + b = 14....(i)

by putting the value of x as (-3), we get,

a(-3)² + 7(-3) + b = 0

=> a(9) - 21 + b = 0

=> 9a + b = 21....(ii)

Now,

subtract (i) from (ii),

9a + b = 21

- 4a ± b = ±14

=> 5a = 7

=> a = 7/5

Putting the value of a in (i),

4a + b = 14

=> 4(7/5) + b = 14

=> 28/5 + b = 14

=> b = 14-28/5

=> b = (70-28)/5

=> b = 42/5

So,

the value of a = 7/5 & b = 42/5

hope it helps.

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