What is the equation of the straight line that passes through (2,1) (5,7)

y = 2x - 3

Step-by-step explanation:

We are asked to find the equation of a straight line

Step 1: find the slope

( 2 , 1) ( 5 , 7)

x_1 = 2

y_1 = 1

x_2 = 5

y_2 = 7

Insert the values into the equation

m = (y_2 - y_1 )/ (x_2 - x _1)

m = (7 - 1 )/ (5 - 2)

m = 6/3

= 2

Step 2: substitute m into the equation

y = mx + c

y = 2x + c

Step 3 : sub any of the two points given into the equation

Let's use ( 2, 1)

x = 2

y = 1

y = 2x + c.

1 = 2(2) + c

1 = 4 + c

c = 1 - 4

c = -3

Step 4: sub c into the equation

y = 2x + c

y = 2x - 3

a. she will receive a refund of $278.

step-by-step explanation: