So for this, I will be using the substitution method. Firstly, subtract both sides in the second equation by 2x: 
Next, substitute y in the first equation with 7-2x, then solve for x from there:

Now that we got x, substitute it into either equation to solve for y:

In short, x = 1/2 and y = 6.
X increases by one
y increases by 2
(5, 1) - > (x + 1, y + 2) -> (6, 3)
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Answers: Choice A and Choice C</h3>
Explanation:
Think of the vertical lines as train tracks (the metal rails).
Stuff between the rails are interior angles.
Angles 3 and 6 are one pair of alternate interior angles because they are on alternating sides of the transversal line. The other pair of alternate interior angles are angles 4 and 5.
Alternate interior angles are congruent when we have parallel lines like this.
1,200 because 4x 3 is 12 and 40 x 30=1,200