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13. The polynomial f(x)=x* - 2x +3x? - ax + b when divided by (x - 1) and (x + 1) Icaves theremainders 5 and 19 respectively. Find the values of a and b. Hence, find the remainder whenf(x) is divided by (x - 3). |
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Answer» Answer: Step-by-step explanation: Let's consider the given expression f(x) = 2x + 3x - ax + b (x-1) when divided leaves remainder 5 So, let x - 1 = 0 x = 1 Hence, f (1) = 2(1) + 3(1) - a(1) + b = 5 2 + 3 - a + b - 5 = 0 5 - a + b - 5 = 0 0 - a + b = 0 Then , b = a. -----------> EQUATION 1 Similarly, (x+1) when divided leaves remainder 19 So, Let x + 1 = 0 x = - 1 Hence, f(- 1) = 2(-1) + 3(-1) - a (-1) + b = 19 - 2 - 3 + a + b = 19 - 5 + a + b - 19 = 0 ( substitute the value of " b " from equation 1 ) - 5 + a + a - 19 = 0 - 24 + 2a = 0 2a = 24 a = 24/2 a = 12 hence , Value of a = 12 value of b = ? but b = a ( from equation 1 ) So, b = 12 Therefore, Value of a = 12 Value of b = 12 This states that , a = b = 12 |
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