How do I find the equation of a linear function that passes through (1, 7) and (2, 9)?

1 Answer
AJ Speller
Sep 17, 2014

For this type of problem we have 3 distinct steps to follow.

1) Find the slope using the formula m=((y_2-y_1))/((x_2-x_1))

2) Find the y-intercept, b, by substituting in the slope , m, from STEP 1 and the x and y values from one of the points given in the slope intercept formula, y=mx+b

3) Substitute the slope, m, and the y-intercept, b, back into the slope intercept formula, y=mx+b.

STEP 1

x_1=1
y_1=7

x_2=2
y_2=9

m=((y_2-y_1))/((x_2-x_1))=((9-7))/((2-1))=2/1=2

STEP 2

y=mx+b

I will use the x and y values from the point (1,7)

7=(2)(1)+b
7=2+b
5=b

STEP 3

y=mx+b

y=2x+5 larr SOLUTION

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