Question

fie functia: f(x)=2x-1. calculati:F(1)+f(2)+......f(5)

Answer 1

 

$\displaystyle\bf\\Se~da:\\f(x)=2x-1\\\\Se~cere:\\f(1)+f(2)+f(3)+f(4)+f(5)=?\\\\f(1)=2\times1-1=1\\f(2)=2\times2-1=3\\f(3)=2\times3-1=5\\f(4)=2\times4-1=7\\f(5)=2\times5-1=9\\\\\boxed{\bf~f(1)+f(2)+f(3)+f(4)+f(5)=1+3+5+7+9=25}$