Instructions: Find the equation of the line through point (2, -1) and
parallel to 2x + 5y = 15. Use a forward slash (i.e. "/") for fractions (e.g. 1/2
for 3).

Answer :

MrRoyal

Answer:

[tex]y = -\frac{2}{5}x -\frac{1}{5}[/tex]

Step-by-step explanation:

Given

Passes through: [tex](2,-1)[/tex]

Parallel to: [tex]2x + 5y = 15[/tex]

Required

First, calculate the slope of the parallel line

[tex]2x + 5y = 15[/tex]

Make y the subject

[tex]5y = 15 - 2x[/tex]

Divide through by 5

[tex]y = 3 - \frac{2}{5}x[/tex]

[tex]y =- \frac{2}{5}x+3[/tex]

An equation in slope intercept has the form:

[tex]y = mx + b[/tex]

Where:

m = slope

[tex]y = mx + b[/tex]

So:

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

The required is parallel to [tex]2x + 5y = 15[/tex].

This mean, the same slope

The equation is the calculated using:

[tex]y - y_1 = m(x - x_2)[/tex]

This gives:

[tex]y - (-1) = -\frac{2}{5}(x - 2)[/tex]

[tex]y +1 = -\frac{2}{5}x +\frac{2}{5}*2[/tex]

[tex]y +1 = -\frac{2}{5}x +\frac{4}{5}[/tex]

[tex]y = -\frac{2}{5}x +\frac{4}{5}-1[/tex]

Take LCM

[tex]y = -\frac{2}{5}x +\frac{4-5}{5}[/tex]

[tex]y = -\frac{2}{5}x -\frac{1}{5}[/tex]

i.e.

[tex]y = -2/3x -1/5[/tex]

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