Put y by itself
3y=6x+2
divide both sides by 3
y=2x+2/3
Just divide 62.31 by three. The subtract the number you get by 3.66. That should be your answer.
Answer:
Check below
Step-by-step explanation:
Hi,
We're dealing with linear functions. 
We have here the first function.

That's a linear function, with slope, and no linear coefficient since
But on the other hand, the functions below, they all describe parallel lines, since their slope has the same value. I've changed the letters to make it easier the comprehension.
Even though each one has the same slope value, they have different non zero linear coefficients, {-6,-18,6,18}. Unlike, the first one

A possible solution would be adjusting any of these, whose operation would result in g(x)=3x, but
Like

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
We want to find the value that makes

To find it we must look at the standard normal table, using the complementary cumulative table we find that

Then, using the z-score we can find the minimum score needed, remember that

Where
σ = standard deviation
μ = mean
And in our example, x = minimum score needed, therefore

Rounding to the nearest integer the minimum score needed is 568, if you get 568 you are at the top 20.1%.