Question

What is the equation of the line that includes (1,8) and (4,2)?

Answer 1

y = -2x + 10

Explanation:

In slope-intercept form:

First, determine the slope using the point-slope formula: (y2-y1)/(x2-x1)

In this case, the slope is -6/3 = -2

Next, you can solve for the intercept by plugging in the numbers to the generic formula: y=mx + b.

y = -2x + b

2 = -2(4) + b

b = 10

Thus the equation for the line is y = -2x + 10

Answer 2

Answer: y = - 2x - 10

Explanation:

The equation of a straight line can be represented in the slope-intercept form, y = mx + c

Where c = y intercept

m represents the slope of the line.

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

y2 = final value of y

y 1 = initial value of y

x2 = final value of x

x1 = initial value of x

The line passes through (1, 8) and (4, 2),

y2 = 2

y1 = 8

x2 = 4

x1 = 1

Slope,m = (2 - 8)/(4 - 1) = - 6/3 = - 2

To determine the y intercept, we would substitute x = 1, y = 8 and m= - 2 into y = mx + c. It becomes

8 = - 2 × 1 + c

8 = - 2 + c

c = 8 + 2

c = 10

The equation becomes

y = - 2x - 10