A geometric sequence is a sequence in which there is a common ratio between any two consecutive terms. In this case if X:Y:Z are in the ratio of 2:7:8 the multiplying by a constant k, we have X=2k, Y= 7k and Z=8k.
Then if X, Y-12, Z form a Geometric sequence, it means X/Y-12=Y-12/Z which is the same as 2k/7k-12=7k-12/8k if we cross multply, we get
16k²= 49k²-168k +144
33k²-168k+144 =0 solving for k
k = 4 or 1.091 if we take the whole number to find the values of X,Y and z,
X= 8, Y= 28 and Z=32
b must be equal to -6 for infinitely many solutions for system of equations
and 
<u>Solution:
</u>
Need to calculate value of b so that given system of equations have an infinite number of solutions

Let us bring the equations in same form for sake of simplicity in comparison

Now we have two equations

Let us first see what is requirement for system of equations have an infinite number of solutions
If
and
are two equation
then the given system of equation has no infinitely many solutions.
In our case,

As for infinitely many solutions 

Hence b must be equal to -6 for infinitely many solutions for system of equations
and
Answer:
32 goldfish
Step-by-step explanation:
Given:
- Number of fish tanks = 8
- Volume of water per fish tank = 5,544 in³
- Water required by 1 goldfish = min 1,386 in³
Number of fish per tank = water per tank ÷ water per goldfish
= 5544 ÷ 1386
= 4
Therefore, each tank can hold a maximum of 4 goldfish.
Greatest number of goldfish = number of tanks × fish per tank
= 8 × 4
= 32
Answer:
It looks like the third one, C
Step-by-step explanation:
Every time c increases by 1, d increases by 2
That means the slope will be 1/2
That means the slope is positive
Which means that there can only be one answer, C