How do you solve # r + 8.2 + 0.4r = -8.6#?

1 Answer
Jan 8, 2016

#r=-12#

Explanation:

To simplify I would suggest multiplying everything by #10# to clear the decimal fractions.
#color(white)("XXX")10r+82+4r=-86#

Subtract #82# from both sides, isolating the #r# factors on one side and the constant s on the other.
#color(white)("XXX")10r+4r=-86-82#

Combine terms on both sides.
#color(white)("XXX")14r = -168#

Divide both sides by #14#
#color(white)("XXX")r=-12#