Question

Write an

equation for the linear function f satisfying the given conditions.
1) f(-1) = -5 and f(5) = 7

Answer 1

Answer: f(x) = 2x - 3

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We're given f(-1) = -5 and f(5) = 7

This means we know the two points (-1,-5) and (5,7) are on the line.

Find the slope

m = (y2-y1)/(x2-x1)

m = (7-(-5))/(5-(-1))

m = (7+5)/(5+1)

m = 12/6

m = 2

The slope is 2.

Use this along with (x1,y1) to find the equation. We'll use point slope form

y - y1 = m(x - x1)

y - (-5) = 2(x - (-1))

y + 5 = 2(x + 1)

y = 2x + 2 - 5

y = 2x - 3

f(x) = 2x - 3