241,443 views
26 votes
26 votes
Given the system of equations:

2x + 2y = 12
X-y= 2
What is x equal to?

8
4
2
1
-2​

User ErikE
by
3.0k points

2 Answers

14 votes
14 votes

answer is 4

because y=2 then you subsistute it in and then you find X

x-y=2 turns to x=y+2 then you subsistute that into x of the equation 2x+2y=12 which then is 2(y+2)+2y =12 and you should get y=2 then you grab the other equation x-2=2 and you should get x=4

User Madhura Jayaratne
by
3.0k points
21 votes
21 votes

Answer:

x=4

y=2

Explanation:

2x+2y=12

x−y=2

​In order to solve by elimination, coefficients of one of the variables must be the same in both equations so that the variable will cancel out when one equation is subtracted from the other.

2x+2y=12,x−y=2

To make 2x and x equal, multiply all terms on each side of the first equation by 1 and all terms on each side of the second by 2.

2x+2y=12,2x+2(−1)y=2×2

Simplify.

2x+2y=12,2x−2y=4

Subtract 2x−2y=4 from 2x+2y=12 by subtracting like terms on each side of the equal sign.

2x−2x+2y+2y=12−4

Add 2x to −2x. Terms 2x and −2x cancel out, leaving an equation with only one variable that can be solved.

2y+2y=12−4

Add 2y to 2y.

4y=12−4

Add 12 to −4.

4y=8

Divide both sides by 4.

y=2

Substitute 2 for y in x−y=2. Because the resulting equation contains only one variable, you can solve for x directly.

x−2=2

Add 2 to both sides of the equation.

x=4

The system is now solved.

x=4,y=2

Correct choice is B) x=4.

User Frank J
by
2.7k points