How do you solve #r-3/10=r/16#?

1 Answer
Jul 9, 2015

Given
[1]#color(white)("XXXX")##r - 3/10 = r/16#

Multiply everything by #160# to clear the fractions (yes, I know #80# would have worked to... but there were no bonus points for using the smallest value).
[2]#color(white)("XXXX")##160r -48 = 10 r#

Add #(48-10r)# to both sides
[3]#color(white)("XXXX")## 150r = 48#

Dividing through by #150#
[4]#color(white)("XXXX")##r = 32%# (or #8/25#)