What is the equation of the line that passes through the given pair points in slope-intercept form?
a. (2, 5.1) and (−1, −0.5)
b. (−2, 3) and (3, −4)

Respuesta :

Louli

Answer:

a. The equation of the line is [tex]y = \frac{28}{15}x+\frac{41}{30}[/tex]

b. The equation of the line is [tex]y = \frac{-7}{5}x+\frac{1}{5}[/tex]

Explanation:

The general equation of the line in slope-intercept form is:

y = mx + c

where m is the slope and c is the y-intercept

1. To get the slope:

[tex]m = \frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]

where (x₁ , y₁) and (x₂ , y₂) are two points that belong to the line

2. To get the y-intercept:

We pick any point (x , y) that belong to the line and use this point to substitute in the general equation:

y = mx + c

m is calculated from part 1 and (x , y) is a known point on the line. So, we solve for c which is the only unknown.

Now, for the required lines:

Part a:

The two given points are (2, 5.1) and (-1, -0.5)

representing (x₁ , y₁) and (x₂ , y₂)

i. Getting the slope:

[tex]m = \frac{-0.5 - 5.1}{-1 -2}=\frac{28}{15}[/tex]

ii. Getting the y-intercept:

I will use the point (-1, -0.5)

y = mx + c

[tex]-0.5 = \frac{28}{15}(-1)+c\\\\-0.5=\frac{-28}{15}+c\\ \\ c = \frac{41}{30}[/tex]

iii. Based on the above calculations, the equation of the line is:

[tex]y = \frac{28}{15}x+\frac{41}{30}[/tex]

Part b:

The two given points are (-2, 3) and (3, -4)

representing (x₁ , y₁) and (x₂ , y₂)

i. Getting the slope:

[tex]m = \frac{-4-3}{3--2}=\frac{-7}{5}[/tex]

ii. Getting the y-intercept:

I will use the point (3, -4)

y = mx + c

[tex]-4 = \frac{-7}{5}(3) + c\\ \\-4 = \frac{-21}{5}+c\\ \\c=\frac{1}{5}[/tex]

iii. Based on the above calculations, the equation of the line is:

[tex]y = \frac{-7}{5}x+\frac{1}{5}[/tex]

Hope this helps :)