if one root of the equation 3x2-kx-2=0 is 2, find the value of k. Also find the other zero
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one root of the equation 3x2-kx-2=0 is 2
x = 2
Place the value of x in 3x2-kx-2=0
3(2)^2 - k(2) - 2 = 0
(3 x 4) - 2k - 2 = 0
12 - 2 - 2k = 0
10 - 2k = 0
10 = 2k
10 / 2 = k
5 = k
Now the equation is 3x^2 -5x - 2 = 0
Factorize :
3x^2 - 6x + x - 2 = 0
3x (x - 2) + 1 (x - 2) = 0
(3x + 1) (x - 2) = 0
3x + 1 = 0 & x - 2 = 0
3x = - 1 & x = 2
x = - 1 / 3 & x = 2
Therefore, the other root is - 1 / 3
one root of the equation 3x2-kx-2=0 is 2
x = 2
Place the value of x in 3x2-kx-2=0
3(2)^2 - k(2) - 2 = 0
(3 x 4) - 2k - 2 = 0
12 - 2 - 2k = 0
10 - 2k = 0
10 = 2k
10 / 2 = k
5 = k
Now the equation is 3x^2 -5x - 2 = 0
Factorize :
3x^2 - 6x + x - 2 = 0
3x (x - 2) + 1 (x - 2) = 0
(3x + 1) (x - 2) = 0
3x + 1 = 0 & x - 2 = 0
3x = - 1 & x = 2
x = - 1 / 3 & x = 2
Therefore, the other root is - 1 / 3
devraoshabh:
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