Grade 4 Math
posted by Riz .
Mele is feeding some of the many exotic fish that live in the coral reefs off the island of Tonga. This is the largest of a chain of islands in the south Pacific. Mele has brought a cooked banana from home to give to the fish. As the fish nibble on the banana, Mele counts 24 fish, some with 5 large green spots and some with 6 blue spots. Altogether she counts 139 spots on the fish that eat her banana. How many of the fish had five spots?

Need help please for my question starting with Mele....
Thanks in advance. 
Let x = 5 spot fish and Y = 6 spot fish.
x + y = 24
Therefore
x = 24  y
Also
5x + 6y = 139
Substitute 24  y for x in the second equation and solve for y. Put value for y in the first equation and solve for x. Check by putting both values into the second equation.
I hope this helps. 
X=5 y=19