Answer:
Option A: y = 10x + 15
Explanation:
Let's find the equation in the form of y=mx+b that fits the data. m is the slope and b is the y-intercept (the value of y when x=0). Slope, m, the the Rise/Run of the line. It can be found by taking any two points from the table. Let's choose (0,15) and (2,35), although any two will work.
x y
0 15
1 25
2 35
3 45
4 55
(0,15) (2,35)
The Rise is the change in y: (35 - 15) = 20.
The Run is the change in x for the same points: (2 - 0) = 2
The slope is the Rise/Run = (20/2) or 10.
The equation has the form y = 10x + b.
Let's find b. Just enter any of the points in the above equation and solve for b. I'll choose (3,45).
y = 10x + b
45 = 10*(3) + b
b = 45 - 30
b = 15
[Note: since b is the value of y when x equals zero, we really didn't need to calculate b as we just did. There is a data point already that tells us the value of y when x = 0: (0,15)]
The equation is y = 10x + 15
Option A: y = 10x + 15