Question

How do you rewrite `15 = 5 y - 4x` so that `y` is a function of `x`?

Answer 1

`y=(15+4x)/5`

Explanation:

My way of approaching it...

1) Flip the side so your "=" sign is on the right (as you'd see in most problems)

`5y - 4x = 15`

2) We need to isolate y so let's try and pry that x out of there, using a little algebra we can just add it to both sides, and we're half-way done already!

`color(blue)(4x+)` `(5y-4x)` = `15` `color(blue)(+4x)`

That first 4x cancels out, giving us...

`5y = 15+4x`

3) Now just one last step, we need y so divide it all by 5

`(5y)/color(blue)(5)` `= (15+4x)/color(blue)(5)`

That first 5 cancels out, giving us...

`y=(15+4x)/5`