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Please help!

Michelle used synthetic division to divide a polynomial f(x) by x-2, as shown:

2 | 1 -7 -3
2 -10
________
1 -5 -13

What is the value of f(2)?

A. -2
B. -3
C. -13
D. -10

Respuesta :

Michelle's result shows f(2) = -13, selection C.

Answer:

C. -13

Step-by-step explanation:

The polynomial f(x) she is dividing would be f(x)=1x²-7x-3.  This is because in synthetic division, the numbers used are the coefficients of the polynomial, and the polynomial will have a degree one larger than the divisor.  Since the divisor is x-2, with a degree of 1, the polynomial will have a degree of 2, meaning it begins with an x².

The first coefficient is 1; this is 1x².  The second coefficient is -7; this is -7x.  The last coefficient is -3; this is -3.  Together, this gives us

f(x) = 1x²-7x-3

To find f(2), substitute 2 in for every x:

f(2) = 1(2²)-7(2)-3 = 1(4)-14-3 = 4-14-3 = -10-3 = -13

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