How do you solve for r: p = 2r - 4?

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Answer 1 · 2017-05-05T12:06:59

See a solution process below:

First, add #color(red)(4)# to each side of the equation to isolate the #r# term while keeping the equation balanced:

#p + color(red)(4) = 2r - 4 + color(red)(4)#

#p + 4 = 2r - 0#

#p + 4 = 2r#

Now, divide each side of the equation by #color(red)(2)# to solve for #r# while keeping the equation balanced:

#(p + 4)/color(red)(2) = (2r)/color(red)(2)#

#(p + 4)/2 = (color(red)(cancel(color(black)(2)))r)/cancel(color(red)(2))#

#(p + 4)/2 = r#

#r = (p + 4)/2#

Or

#r = p/2 + 4/2#

#r = p/2 + 2#