The equivalent expression -
4n + 19
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:
693.6
Step-by-step explanation:
Answer:
1. Proved down
2. proved down
3. f(10) = -20 - 5 - 5 - 5 - 5 - 5 - 5 - 5 - 5 - 5 - 5
Step-by-step explanation:
Let us explain how to solve the question
∵ f(0) = -20, f(n) = f(n - 1) - 5 for n > 1
→ That means we have an arithmetic sequence with constant
difference -5 and first term -20
1. → f(1) means we need to find the second term, which equal the
term - 5
∵ f(1) means n = 1
∴ f(1) = f(1 - 1) - 5
∴ f(1) = f(0) - 5
∵ f(0) = -20
∴ f(1) = -20 - 5 → Proved
2. → f(3) means we need to find the third term, which equal the
second term - 5
∵ f(3) means n = 3
∴ f(3) = f(3 - 1) - 5
∴ f(3) = f(2) - 5
→ f(2) = f(1) - 5
∵ f(1) = -20 - 5
∴ f(2) = [-20 - 5] - 5 = -20 - 5 - 5
∴ f(3) = [-20 - 5 - 5] - 5
∴ f(3) = -20 - 5 - 5 - 5 → Proved
3. → From 1 and 2 we notice that the number of -5 is equal to n,
at n = 1 there is one (-5), when n= 3 there are three (-5)
∵ n = 10
∴ There are ten (-5)
∴ f(10) = -20 - 5(10)
∴ f(10) = -20 - 5 - 5 - 5 - 5 - 5 - 5 - 5 - 5 - 5 - 5 → Proved
Answer:
a = 6/5
b = 7/8
c = 1/5
Step-by-step explanation:
We want to make two of these equations be in terms of the same variable, so let's solve the first and third in terms of b.
5a-24b=-15 -> -3 + 24b/5 = a
48b+35c = 49 -> 49/35 - 48b/35 = 7/5 - 48b/35 = c
Now we can replace the a and c in the second equation and solve for b.
10a+45c=21
10(-3+24b/5)+45(7/5 - 48b/35) = 21
-30 + 48b + 63 - 432b/7 = 21 -> -12 = -96b/7 -> b=7/8
Now we can plug b back into the other two to solve for a and c. I will leave that to you unless you would like the steps there.
