The notation f(ln 2, ln 3 , ln 5) means that the values of the variables are x= ln 2 , y = ln 3 and z = ln 5.
So to evaluate a function, plug-in the values of the variables.
`f(x,y,z)=xye^z+xze^y+yze^x`
`f(ln 2, ln 3 , ln 5)=ln2 * ln3*e^(ln5) + ln2*ln5e^(ln3) + ln3*ln5e^(ln2)`
Note that `e^(lna)=a` .
`f(ln 2, ln 3 , ln 5)=ln2*ln3*5+ln2*ln5*3+ln3*ln5*2`
`f(ln2,ln3,ln5)=5ln2*ln3+3ln2*ln5+2ln3*ln5`
`f(ln 2, ln 3 , ln 5)=10.69`
Hence, `f(ln 2, ln 3 , ln 5)=10.69 ` .