Which of the following equations represents the equation in slope-intercept form for a line that passes through the points (-10, 3) and (-5, 4)?

Responses

A y = 0.2x + 5y = 0.2 x + 5

B y = 5x + 29y = 5 x + 29

C y = 0.2x + 3y = 0.2 x + 3

D y = 5x – 21

1 answer

To find the slope-intercept form of the equation that passes through the points \((-10, 3)\) and \((-5, 4)\), we first need to calculate the slope \(m\) using the formula:

\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]

Using the points \((-10, 3)\) \((x_1, y_1)\) and \((-5, 4)\) \((x_2, y_2)\):

\[ m = \frac{4 - 3}{-5 - (-10)} = \frac{1}{-5 + 10} = \frac{1}{5} \]

So the slope \(m\) is \(\frac{1}{5}\).

Next, we want to use the slope-intercept form of the equation, which is:

\[ y = mx + b \]

We already have \(m = \frac{1}{5}\). Now we can use one of the points to find \(b\). We can use either point; let's use \((-10, 3)\):

\[ 3 = \frac{1}{5}(-10) + b \]

Calculating this gives:

\[ 3 = -2 + b \]

Solving for \(b\):

\[ b = 3 + 2 = 5 \]

Thus, the equation in slope-intercept form is:

\[ y = \frac{1}{5}x + 5 \]

Now, let's check the options given:

A. \(y = 0.2x + 5\) (which is equivalent to \(y = \frac{1}{5}x + 5\))

B. \(y = 5x + 29\)

C. \(y = 0.2x + 3\)

D. \(y = 5x - 21\)

The only equation that matches our derived equation is option A: \(y = 0.2x + 5\).