Question

PLEASE I NEED HELP WITHIN 5 MINUTES!!! After 4 minutes of reading, Aaron was on page 14 of his book. After 8 minutes he was on page 20. Which equation models the page number, y in terms of minutes x?
A. y=-8x+1.5
B. y=1.5x+8
C. y=8x+1.5
D. y=-1.5x+8

Answer 1

Answer:

  B.  y = 1.5x +8

Step-by-step explanation:

You can try x=4 in the various equations to see which gives the right value (14).

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A: y = -8(4) +1.5 = -30.5

B: y = 1.5(4) +8 = 14 . . . . . . . . .  this equation works

C: y = 8(4) +1.5 = 33.5

D: y = -1.5(4) +8 = 2

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Alternatively, you can use the 2-point form of the equation of a line to write the equation:

  y = (y2 -y1)/(x2 -x1)(x -x1) +y1

  y = (20 -14)/(8 -4)(x -4) +14 . . . . fill in (x1, y1) = (4, 14); (x2, y2) = (8, 20)

  y = 1.5(x -4) +14 . . . . . simplify somewhat

  y = 1.5x +8 . . . . . . . . write in slope-intercept form