Question 109420
Something is missing. You've written 18x^? Should a 2 be here? I'm going to assume that a 2 should be here.



{{{f(x)=18x^2-12x-3}}} Start with the given function



{{{f(2/3)=18(2/3)^2-12(2/3)-3}}} Plug in {{{x=2/3}}}



{{{f(2/3)=18(4/9)-12(2/3)-3}}} Square{{{2/3}}} to get {{{4/9}}}



{{{f(2/3)=72/9-12(2/3)-3}}} Multiply 18 and {{{4/9}}} to get {{{72/9}}}



{{{f(2/3)=8-12(2/3)-3}}} Reduce



{{{f(2/3)=8-24/3-3}}} Multiply 12 and {{{2/3}}} to get {{{24/3}}}



{{{f(2/3)=8-8-3}}} Reduce



{{{f(2/3)=-3}}} Combine like terms



So when {{{x=2/3}}}, {{{f(x)=-3}}}