Answer:
x = 21
Step-by-step explanation:
corresponding sides in similar polygons are proportional:
set a proportion: BC/FK = CA/KJ => 18/6 = x/7 => x = 18 × 7 ÷ 6 = 21
There are 3 ways of solving a simultaneous problem, substitution method, elimination method and Gauss-Jordan method. I'm gonna use the substitution method since it's easier and i think it would suit your level more.
First let's try solving for y since it's easier to start with.
Firstly we have to find an equation for x:

Great, now we can use the substitution method to find the value of y using the first equation:

Now we know that y=1 we can solve the first equation we made:

And the answer is 
Double check:

And that's our final answer! (4,1)
Can you list the options? so i can help, theres not enough info for me to answer
<h3><u>MEAN</u></h3>
Mean is the average. To find the mean of a data set, you have to add all the numbers and divide the sum by the amount of numbers you added.
<em>In this equation, you have 8 numbers. That means you will be dividing by 8. </em>
The first thing you need to do is add all the numbers. Add:

Now that you have added all the numbers and got the sum, divide by 8. Remember that you will be dividing by 8 since you added 8 numbers.
Divide:

The mean is 66
<em>If you have any questions, feel free to ask in the comments! :)</em>
Answer:
36π cubic inches
Step-by-step explanation:
V = 4/3 πr³
radius (r): 3
= 4/3π(3)³
= 4/3π (27)
= 36π