You can make some algebraic equations and solve it.
The first would be:

The second would be

You can then rearrange the second into

And subsitute it into the first like so:

After that, distribute the y into the parantheses.

Subtract the 21 on both sides and multiply by -1 on both sides:

You then can factor it into:

With Zero Product Property, we can determine y to be either -3 and 7. Since the variables are interchangable, you can say the same about x, just that whatever x is, y must be the other value.
Thus, the answer is 7 and -3.
3x-4y=10
or,4y=3x-10
or,y=(3x-10)/4
so,y=3/4 x-5/2
Answer:
3.2
Step-by-step explanation:
3.21428571429 is the exact answer and rounded to the nearest tenth is the first number after the decimal.
I think the best answer is AB
3x + 7 = x
First, subtract 3x from both sides. / Your problem should look like: 7 = x - 3x
Second, simplify x - 3x to -2x. / Your problem should look like: 7 = -2x
Third, divide both sides by -2. / Your problem should look like:

= x
Fourth, simplify

to

/ Your problem should look like:

= x
Fifth, switch sides. / Your problem should look like: x =

Answer as fraction:

Answer as decimal: -3.5