Question 143763
f(x) is DECREASING, so it is "moving downhill" as x moves to the right.  
Since f(5)=7, for any value of x that is less than 5, the value of the function will be MORE THAN 7.  For any value of x that is more than 5 (that is to the RIGHT of 5!), the value of the function will be LESS THAN 7 since the function must continue to decrease.


Therefore, f(0) must be greater than 7. 


R^2