2 is a root of the equation 2x^3 - 5kx^2 +7x +10 = 0, find the value of k.
Its easy but I forgot how to do this question. Can someone show me how to do this equation and the steps. Thanks!
Its easy but I forgot how to do this question. Can someone show me how to do this equation and the steps. Thanks!
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Substitute x = 2.
Since 2 is a root we should get 0.
2(2)³ - 5k(2)² + 7(2) + 10 = 0
16 - 20k + 14 + 10 = 0
40 - 20k = 0
k = 2
Since 2 is a root we should get 0.
2(2)³ - 5k(2)² + 7(2) + 10 = 0
16 - 20k + 14 + 10 = 0
40 - 20k = 0
k = 2
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If x = 2 is a root then
P(x) = 2x^3 - 5kx^2 +7x +10 due to P(2) = 0
P(2) = 16 - 20k +14 +10 = 40-20k = 0 then k = 2
P(x) = 2x^3 - 10x^2 +7x +10 = 2x^2(x-2)- 6x(x-2) - 5(x-2) = (x-2)(2x^2 - 6x -5)
P(x) = 2x^3 - 5kx^2 +7x +10 due to P(2) = 0
P(2) = 16 - 20k +14 +10 = 40-20k = 0 then k = 2
P(x) = 2x^3 - 10x^2 +7x +10 = 2x^2(x-2)- 6x(x-2) - 5(x-2) = (x-2)(2x^2 - 6x -5)
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solve f(2) = 0