Once cross multiplied you end up with this:
15x+75=20x−30
Next subtract 20x from both sides.
15x+75−20x=20x−30−20x
−5x+75=−30 -----------> Answer
Now subtract 75 from both sides
−5x+75−75=−30−75
−5x=−105
Now divide by -5 on both sides.
-5/-5x = -105/-5
<h3 /><h3>
x = 21 --------------> ANSWER</h3>
<h2>
Answer with explanation:</h2>
We are asked to prove by the method of mathematical induction that:

where n is a positive integer.
then we have:

Hence, the result is true for n=1.
- Let us assume that the result is true for n=k
i.e.

- Now, we have to prove the result for n=k+1
i.e.
<u>To prove:</u> 
Let us take n=k+1
Hence, we have:

( Since, the result was true for n=k )
Hence, we have:

Also, we know that:

(
Since, for n=k+1 being a positive integer we have:
)
Hence, we have finally,

Hence, the result holds true for n=k+1
Hence, we may infer that the result is true for all n belonging to positive integer.
i.e.
where n is a positive integer.
Answer:
each shirt is $4.20
Step-by-step explanation:
42/10 = 4.2
Answer:

Step-by-step explanation:
First, we need to isolate
by taking it common from both terms on the right:

Now, since we want
in terms of the other variables, we can divide the left hand side (A) by whatever is multiplied with
on the right hand side. Then we will have an expression for
. Shown below:

This is the xpression for 