Answer: Choice A) y = 2x
slope = 2, y intercept = 0
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Explanation:
We can see this by noting that each y coordinate is simply doubled that of the x coordinate.
- x = 1 doubles to y = 2
- x = 2 doubles to y = 4
So in general, x doubles to 2x to get the y coordinate. Therefore, y = 2x.
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Alternative method:
A more thorough step by step process would have us first finding the slope
m = (y2 - y1)/(x2 - x1)
m = (4 - 2)/(2 - 1)
m = 2/1
m = 2 is the slope
Use this slope value along with one of the points to find b. I'll use the point (x,y) = (1,2)
So,
y = mx+b
2 = 2*1+b
2 = 2+b
2-2 = b
0 = b
b = 0 is the y intercept
We go from y = mx+b to y = 2x+0, which simplifies to y = 2x
