there are 30 fish in a tank. the fish are either orange or red. there are 12 more orange fish than the number of red fish, how many fish are orange? how many fish are red?

The number of red fish are 9

Step-by-step explanation:

X = number red fish

Y = number orange fish

then,

X + Y = 30

Y = 12 + X

then replacing Y

X + (12 + X) = 30

2X = 18

X = 9

Best regards