How do you solve #-b + \frac { 8} { 5} b = 9?#

2 Answers
Sep 30, 2017

Given: #-b + 8/5b = 9#

Combine like terms:

#3/5b = 9#

Multiply both sides of the equation by #5/3#:

#b = (5/3) 9#

#b = 15#

Check:

#-(15) + 8/5(15) = 9#

#-15 + 8(3) = 9#

#-15+24=9#

#9 = 9#

This checks.

Sep 30, 2017

#-b+(8b)/5=9#
#-5b+8b=45#
I transferred 5 from LHS to RHS, and when we do that or vice versa, we inverse it, i.e. if addition then subtraction(and vice versa), if multiplication then division(and vice versa).

Also note that when doing -5b+8b, it seems a little complex, do it is also equal to 8b-5b, which seems a lot simpler.
#3b=45#
#b=45/3#
#b=15#