Answer and explanation:
1. 9:12 or 
or 9 to 12
It has 9 first because there are 9 lions and then 12 after because there are 12 elephants.
2. 8:16 or 
or 8 to 16
It has 8 first because there are 8 giraffes and then 16 after because there are 16 otters.
3. 9:10 or 
or 9 to 10
It has 9 first because there are 9 lions and then 10 after because there are 10 seals.
4. 10:12 or 
or 10 to 12
It has 10 first because there are 10 seals and then 12 after because there are 12 elephants.
5. 12:9 or 
or 12 to 9
It has 12 first because there are 10 elephants and then 9 after because there are 9 lions.
6. 
or 
or 
I just multiplied it first the first one by 2, second one by 10, and 3rd one by 4.
7. 
or 
or 
I just simplified it first, then I multiplied the simplified one by 6 for the second one, and for the 3rd one I multiplied the simplified by 10.
8. 
or 
or 
I just simplified it first, then I multiplied the simplified one by 2 for the second one, and for the 3rd one I multiplied the simplified by 10.
9. 3:4 is equivalent to 6:8, 30:40, 12:16
I multiplied it first by 2, then by 10, then by 4.
10. 5:7 is equivalent to 10:14, 50:70, 25:35
I multiplied it first by 2, then by 10, then by 5.
11. 9:2 is equivalent to 18:4, 90:20, 27:6
I multiplied it first by 2, then by 10, then by 3.
12.
a. 48
So first, the ratio we know is 5:4 which in other words is 5x:4x. We also know that there are 60 clownfish. So that means 5x = 60 --> x = 12. So then 4x has to equals 12 x 4 which is 48.
b. 36
So first, the ratio we know is 4:3 which in other words is 4x:3x. We also know that there are 48 angelfish. So that means 4x = 48 --> x = 12. So then 3x has to equals 12 x 3 which is 36.
Hope this helped! <3
