Write the equation of the line through the points (1, -1) and (3, 5).

Answer: The equation of the line is y=3x−4y = 3x - 4.

Step-by-step solution

Step 1: Calculate the slope

The slope mm of a line passing through two points (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is given by the formula for the change in yy divided by the change in xx. We will use the given points (1,−1)(1, -1) and (3,5)(3, 5) to calculate the slope.

Step 2: Substitute coordinates to find slope

Substitute the coordinates of the given points (x1,y1)=(1,−1)(x_1, y_1) = (1, -1) and (x2,y2)=(3,5)(x_2, y_2) = (3, 5) into the slope formula. This gives us a slope of 3.

Step 3: Use the point-slope form

Now that we have the slope, we can use the point-slope form of a linear equation. This form requires the slope mm and one point (x1,y1)(x_1, y_1) on the line.

Step 4: Substitute slope and a point

Substitute the calculated slope m=3m=3 and one of the given points, for example (1,−1)(1, -1), into the point-slope form. This will allow us to simplify the equation into the standard slope-intercept form.

Step 5: Simplify to slope-intercept form

Simplify the equation by distributing the slope and isolating yy to get the equation in the slope-intercept form, y=mx+cy = mx + c.

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