Step 1 is wrong it should be: 2x - 3x - 1=3

Actually Welcome to the Concept of the Inequalities.
so we get as,
(w+6)/2 < 5
so we get as,
w+6 < 10
=> w < 10-6
=> w < 4
so the answer is,
w < 4
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
Answer:
It appears to be substitution
Step-by-step explanation:
I think you are talking about system of equations