Question 318104
i)


{{{f(x)=2x^2-x+1}}} Start with the given function.



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



{{{f(a+1)=2(a^2+2a+1)-(a+1)+1}}} FOIL.



{{{f(a+1)=2a^2+4a+2-a-1+1}}} Distribute.



{{{f(a+1)=2a^2+3a+2}}} Combine like terms.


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ii)


{{{f(x)=2x^2-x+1}}} Start with the given function.



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



{{{f(3b)=2(9b^2)-3b+1}}} Square 3b to get {{{9b^2}}}.



{{{f(3b)=18b^2-3b+1}}} Multiply 2 and {{{9b^2}}} to get {{{18b^2}}}