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HELP ME PLSSSSSS , MY DEADLINE IS NOW PLS HELPPP

Multiple choice :
A) 0
B) 2
C) -1.5
D) 4
E) 0.5


HELP ME PLSSSSSS , MY DEADLINE IS NOW PLS HELPPP Multiple choice : A) 0 B) 2 C) -1.5 D-example-1

1 Answer

4 votes

Answer: Choice E) 0.5

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Step-by-step explanation:

The given equation is in the form of ax^2+bx+c = 0

The coefficients are

  • a = 2
  • b = k
  • c = -3

According to Vieta's formula, we know that the roots of a quadratic multiply to c/a

In this case, the roots multiply to -3/2

Let p and q be the two roots. We're told that -3 is one of the roots, so p = -3. Let's find q.

pq = c/a

-3q = -3/2

q = (-3/2)*(-3/1)

q = 1/2

q = 0.5

The other root is 0.5

The product of the roots is -3*0.5 = -1.5 = -3/2 to confirm the answer.

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The longer way to solve would be to plug x = -3 into the equation and solve for k. You should get k = 5

Once you know the value of k, use the quadratic formula to find the two roots. You should get -3 and 1/2 = 0.5 as the two roots.

User Sindhara
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