Question

Write an equation of the line that is parallel to 5x + 20y = 10 and passes through the point (8, 3).

Answer 1

Put the first equation into y= mx + b form:
5x + 20y = 10

Subtract 5x from both sides:
20y = 10 - 5x

Divide both sides by 20:
y = 1/2 - (1/4)x
y = -(1/4)x + 1/2

This means -1/4 is your slope. To be parallel, the new equation must have the same slope.

Start with: y = -(1/4)x + b

Plug in 8 for the x and the 3 for the y:
3 = -(1/4)(8) + b
3 = -2 + b

Add the 2 to both sides:
5 = b

Your answer is:
y = -(1/4)x + 5