If f(x)=-2xsquared+x-5 what is f(3)

9514 1404 393

  -20

Step-by-step explanation:

Put 3 where x is and do the arithmetic.

  f(3) = -2·3² +3 -5

  f(3) = -2·9 +3 -5 = -18 +3 -5 = -15 -5

  f(3) = -20

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Sometimes it is easier to evaluate polynomials when they are written in Horner form:

  f(x) = (-2x +1)x -5

  f(3) = (-2·3 +1)(3) -5 = -5(3) -5 = -20