Question

A two week old puppy weighs 11 ounces. Two weeks later, it weighs 15 ounces. Right in equation to represent the weight y of the puppy X weeks after birth.

Answer 1

y = 2x +7

Explanation:

We are given two points on the growth curve: (weeks, ounces) = (2, 11) or (4, 15).

These can be used to write the equation of a line using the 2-point form:

y = (y2 -y1)/(x2 -1x)(x -x1) +y1

y = (15 -11)/(4 -2)(x -2) +11

y = 4/2(x -2) +11

y = 2x +7 . . . . . y = weight in ounces x weeks after birth

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Comment on the problem

There are an infinite number of equations that can be written to go through the two given points. A linear equation is only one of them.