How do you solve #\frac { 12} { 5} ( r - 2) = \frac { 2} { 3} [ 3r - 2( 2r - 1) ]#?

1 Answer
Dec 28, 2016

r = 2

Explanation:

#12/5(r-2) = 2/3(3r-2(2r-1))#

To make it easier, try to eliminate the denominators by cross multiplying.

#12(r-2) xx3 = 2(3r-2(2r-1))xx5#

#36(r-2) = 10(3r-2(2r-1))#

Expand the brackets on both sides

#36r-72 = 10(3r-4r+2)#
#36r-72 = 30(-r+2)#
#36r-72 = -30r+60#

Rearrange #r# to one side and numbers to another side.

#36r+30r = 60+72#
#66r = 132#

divide by 66 on both sides.

#r = 132/66#

#r = 2#