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If polynomials ax3 + 3x2 - 3 and 2x3 - 5x + a when divided by (x - 4) leave the remainders as R1 and R2 respectively. Find the values of a in 2R1 - R2=0
A polynomial is an algebraic expression that has constants, variables, and coefficients with a point where the value of the polynomial becomes zero as a whole.
Answer: The value of a in 2 R1 - R2 = 0 is 18 / 127.
Here's the step-by-step solution.
Explanation:
Let f( x ) = ax3 + 3x2 - 3 and g( x ) = 2x3 - 5x + a
Given that f( x ) and g( x ) when divided by x - 4 leaves the remainders R1 and R2 respectively.
By remainder theorem, substituting the value x = 4 in both f( x ) and g( x ), we get remainders.
For f( 4 ) = ax3 + 3x2 - 3
= a × ( 4 )3 + 3 × ( 4 )2 - 3 = 64 a + 48 - 3
= 64 a + 45 = R1 (eq 1)
For g( 4 ) = 2x3 - 5x + a
= 2 × ( 4 )3 - 5 × ( 4 ) + a = 128 - 20 + a
= 108 + a = R2 (eq 2)
Given that 2R1 - R2 = 0
Therefore, from eq 1 and eq 2
2 ( 64 a + 45 ) - ( 108 + a ) = 0
⇒ 128 a + 90 - 108 - a = 0
⇒ 127 a - 18 = 0
⇒ 127 a = 18
⇒ a = 18 / 127
Thus, the value of a in 2 R1 - R2 = 0 is 18 / 127.
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