How do you solve for y in #9-y=1.5x#?

1 Answer
Dec 29, 2015

Answer:

#9 = 1.5x + y#
#y = 9 - 1.5x#

OR

#-y = 1.5x - 9#
#-1(-y) = -1(1.5x - 9)#
#y = 9 - 1.5x#

Explanation:

There are two methods for rearranging this equation.

Term Transaction

  1. Add #y# to both sides of the equation:
    #9 = 1.5x + y#
  2. Subtract #1.5x# from both sides of the equation:
    #9 - 1.5x = y" or "y = 9 - 1.5x#

Notice that the variables have simply changed places and reversed their signs.

Multiply through by #-1#

  1. Subtract 9 from both sides of the equation:
    #-y = 1.5x - 9#
  2. Multiply both sides of the equation by #-1#:
    #-1(-y) = -1(1.5x - 9)#
    #y = -1.5x + 9" or "y = 9 - 1.5x#