How Do You Begin To Figure Grape-plum=apple?

EASY!
GRAPE                              if e - m = e, m has to equal 0.      GRAPE-PLU0=APPLE
- PLUM                              it is impossible for g - 0 = a. Therefore, a connote be 9
APPLE                              r connote be 9. G cannot be 1.
                                        Since you borrow, r is 4 and p is 7 G4A7E+7LU0=A77LE
                                        so far, so good
                                        try plugging G with 9 and A with 8 and you with 6
                                        9487E+7L60=A77LE
                                        I can't give away the answer, but I can tell you this much. Hopefully this has helped you solve the problem on your own.