Question

A line passes through the points (3,15) and (7,19). Write a linear function rule in terms of x and y
for this line.

Answer 1

Answer:

y = x + 12

Step-by-step explanation:

Find the slope using the two given points.

  x      y

 3      15

  7     19

Rise = (19-15) = 4

Run = (7-3) = 4

Slope = Rise/Run = (4/4) or 1

We have y = mx + b, where m, the slope, is 1

y = 1x + b

Find the y-intercept by substituting one of the two given points and solve for b:

Rearrange y = 1x + b

b = y - 1x

b = 15 - 1*(3)    [I used point (3,15)]

b = 12

The equation is y = x + 12

See attachment.