Question 87258
{{{f(x)=-2x^3-8x^2+2x-1}}} Start with the given polynomial



{{{f(-3)=-2(-3)^3-8(-3)^2+2(-3)-1}}} Plug in {{{x=-3}}}



{{{f(-3)=-2(-27)-8(-3)^2+2(-3)-1}}} Raise -3 to the third power to get -27



{{{f(-3)=-2(-27)-8(9)+2(-3)-1}}} Raise -3 to the second power to get 9



{{{f(-3)=--54-8(9)+2(-3)-1}}} Multiply 2 by -27 to get -54



{{{f(-3)=--54-72+2(-3)-1}}} Multiply 8 by 9 to get 72



{{{f(-3)=--54-72+-6-1}}} Multiply 2 by -3 to get -6



{{{f(-3)=-25}}} Now combine like terms


Notice if we graph {{{f(x)=-2x^3-8x^2+2x-1}}} and the point (-3,-25) we get


{{{ drawing(900, 900, -10, 5, -30, 5,
graph( 900, 900, -10, 5, -30, 5, -2x^3-8x^2+2x-1),
circle(-3,-25,0.05),
circle(-3,-25,0.08)) }}}


and we can see that (-3,-25) is on the curve. So this verifies our answer