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Find the value of the constant K if 4x³ + kx² + 7x - 23 have a remainder 7 when divided by 2 x - 5​

User DBoyer
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1 Answer

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Final answer:

The value of the constant K is -5.2.

Step-by-step explanation:

We can use the factor theorem to find the value of the constant K. According to the factor theorem, if a polynomial f(x) has a remainder of c when divided by the binomial (ax - b), then f(b/a) = c. In this case, the polynomial is 4x³ + kx² + 7x - 23 and the binomial is 2x - 5. So, we set f(5/2) = 7 and solve for K:

f(5/2) = 4(5/2)³ + k(5/2)² + 7(5/2) - 23 = 7

Simplifying this equation:

(125/2) + (25/2)*k + (35/2) - 23 = 7

125/2 + (25/2)*k + 35/2 - 46/2 = 7

(125 + 25k + 35 - 46)/2 = 7

(144 + 25k)/2 = 7

144 + 25k = 14

25k = -130

k = -5.2

User Ccamacho
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