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

1 Answer
Nov 28, 2017

#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#