Answer:
16.5?
Step-by-step explanation:
It's halfway between 16 and 17?
So first create and define your variables:
Z = amount of zebra fish
N = amount of neon tetras
Now create your equations:
2z+2.15n=31.20
z+n=15
This is your system. There are multiple methods to use but in this problem I’ll use the substitution method by simplifying the bottom equation.
2z+2.15n=31.20
z=15-n
Now I’ll plug the bottom equation into the top one.
2(15-n)+2.15n=31.20
And just solve from here.
30-2n+2.15n=31.20
0.15n=1.20
n=8
So he bout 8 neon tetras, and 15-8= 7, so he bought 7 zebra fish
18:24 = 3/4
4:70 = 2/35
35:105 = 1/3
22:7 = 22/7
12:165 = 4/55
D. It Is The Most Fitting Answer. The Other 3 Equal More Than Needed.