Equation: x+2x+(2x+8)=148
Solve for x: 5x+8=148
5x=140
x=28
Plug back into original equation to find the other two amounts:
28+2(28)+[2(28)+8]=148
Cecilia = 28, Oscar = 56, Tasha = 64
Check: 28+56+64= 148
148=148
The solutions work
Cecilia has 28 fish, Oscar has 56 fish, and Tasha has 64 fish