Answer:
or 
Step-by-step explanation:
Substitution means plugging in one variable's value that consists of the opposite variable. Because
is already specified, you can plug it into the second equation's
value. After doing that, it looks like this:

Then you would distribute the
across the parentheses next to it, like this:

Then, add like terms, like this:

Then divide both side by
to isolate
.

Now, you can plug
(
) into either equation, but the first one seems simpler so you would pick that. It would look like this:

Solving would look like this:

So the answer is
or
.
Answer:
A) But if anyone thinks this they should go back to preschool
Step-by-step explanation:
On any other value of x you would take the numerators and denominators and multiply them across:

But, this literally does not make since considering the fact that you cannot divide any value by zero. Try it, it won't work. If we plug these into a trusty dusty calculator, we get this:

0*DOMAINERROR= You can't do it.
There are other reasons why you can't divide by zero, I would suggest looking them up on YT and learning about them.
I would answer A, but the person who wrote this question just wasn't focusing when they wrote the question.
Answer:
Step-by-step explanation:
Answer:
The amount of steel used = 94.38 
Step-by-step explanation:
Height of the tank = 4.5 m.
Diameter of the tank = 4.2 m.
But,
radius = 
= 
radius = 2.1 m
Total surface area of a cylinder = 2
rh + 2

= 2
r(r + h)
= 2 x
x 2.1 (2.1 + 4.5)
= 44 x 0.3 (6.6)
= 87.12
Total surface area of a cylinder = 87.12 
Since
of the steel was wasted, then;
x 87.12 = 7.26 
Actual area of steel sheet used = 87.12 + 7.26
= 94.38 
Thus, 94.38
of steel was used in making the tank.
The amount you save is : $119 (usd im so sorry, i tried to do it in £ but i had a hard time with the different currencies.) so, the sale price is : $51 usd