Y=-4*b*b+5.0/9.0*(a/b)+10

Hello guys, this is an equation that I should program in C++. This is the form that I have entered: Y=-4*b*b+5.0/9.0*(a/b)+10; and for a=2 and b=3.4 I get the result -35.9132 while in my calculator the result is −35.259608. Can someone help me with finding the error cuz I am not sure what it is.