Answer:
...2 grapes-1apple=7
1 grapes-1 part watermelon =1
yellow fruit (I don't know) = 5
1 yellow fruit + 1 part of watermelon = 9
--->1 part of watermelon = 9-5=4
1 grape-1 part of watermelon =1
1grape-4=1
1 grape = 1+4=5
2 grapes-1 apple = 7
5*2 - 1apple = 7
10-1apple=7
-1apple=7-10
1apple =3
Explanation: