We are given the system of equations -:

Since the second equation is y-isolated equation. It can be substituted as y = 6x+22 in the first equation.

Expand 3 in the expression so we can combine like terms and isolate x-variable.

Then combine like terms.

Get rid of 66 from the left side by subtracting both sides by itself.

To finally isolate the variable, divide both sides by 20 so we can leave x only on the left side.

Simplify to the simplest form.

Normally, we have to find the y-value too but since we only find x-value. The answer is x = -4.
Answer
I hope this helps! If you have any questions or doubts regarding my answer, explanation or system of equations, feel free to ask!
The variable was whether people approve or disapprove of the president. They were trying to poll just the people that live in the main part of the USA. There is slight bias that comes from excluding Alaska and Hawaii.
Answer:
x=-6
Step-by-step explanation:
2x+y=-4
5x+3y=-6
solve :
multiply first equation by 3
6x+3y=-12
5x+3y=-6
subtract the two equations : 6x+3y-5x-3y=-12-(-6)
x=-12+6
x=-6
X + y = 40.....multiply by -4
4x + 6y = 180
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-4x - 4y = -160 (result of multiplying by -4)
4x + 6y = 180
------------------add
2y = 20
y = 20/2
y = 10 <===
x = 30