The last "Plus" is too much
In[83]:= (3/2)/(-9/14) + 2 (1/5) Out[83]= -(29/15)
Not quite. It should be:
(3/2)/(-9/14) + 2 + 1/5
Use round brackets, ( ), to indicate precedence. Spaces between two numbers are taken as Times, so 2 1/5 becomes (2*1)/5. In fact, in an Input cell it should show a gray "x" symbol standing for Times.
