We have the function:
[tex]f(x)=2x^2+3x-5[/tex]And we have to find f(4), this is the value of the function when x=4.
To do that we have to replace the x's in the equation by the value 4:
[tex]f(4)=2(4)^2+3(4)-5=2\cdot16+12-5=32+12-5=44-5=39[/tex]The value of f(4) is 39.