Which equation represents the line that passes through the points [tex]$(2,3)$[/tex] and [tex]$(4,7)$[/tex]?

A. [tex]2x - y = -1[/tex]
B. [tex]2x + y = -1[/tex]
C. [tex]2x - y = 1[/tex]
D. [tex]2x + y = 1[/tex]



Answer :

To determine which equation represents the line passing through the points [tex]\((2, 3)\)[/tex] and [tex]\((4, 7)\)[/tex], let's follow these steps:

1. Calculate the Slope (m):
The slope [tex]\( m \)[/tex] of a line passing through two points [tex]\((x_1, y_1)\)[/tex] and [tex]\((x_2, y_2)\)[/tex] is given by:
[tex]\[ m = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]
Here, substituting in the given points [tex]\((x_1, y_1) = (2, 3)\)[/tex] and [tex]\((x_2, y_2) = (4, 7)\)[/tex]:
[tex]\[ m = \frac{7 - 3}{4 - 2} = \frac{4}{2} = 2 \][/tex]

2. Point-Slope Form:
Using the slope [tex]\( m \)[/tex] and one of the points, e.g., [tex]\((2, 3)\)[/tex], we can write the equation of the line in point-slope form, which is:
[tex]\[ y - y_1 = m(x - x_1) \][/tex]
Substituting [tex]\( m = 2 \)[/tex] and the point [tex]\((2, 3)\)[/tex]:
[tex]\[ y - 3 = 2(x - 2) \][/tex]

3. Convert to Slope-Intercept Form:
Rearranging this equation into the slope-intercept form [tex]\( y = mx + b \)[/tex]:
[tex]\[ y - 3 = 2x - 4 \][/tex]
[tex]\[ y = 2x - 1 \][/tex]

4. Convert to Standard Form:
To convert the slope-intercept form to the standard form [tex]\( Ax + By = C \)[/tex]:
[tex]\[ y = 2x - 1 \implies 2x - y = 1 \][/tex]

Therefore, the standard form of the equation representing the line passing through the points [tex]\((2, 3)\)[/tex] and [tex]\((4, 7)\)[/tex] is:

[tex]\[ \boxed{2x - y = 1} \][/tex]

From the options provided, the correct answer is:
[tex]\[ 2x - y = 1 \][/tex]