How do you solve #-\frac { 2} { 3} c - 7= - 9#?

1 Answer
Feb 4, 2017

#c=3#

Explanation:

To eliminate the fraction, multiply ALL terms on both sides of the equation by 3, the denominator of the fraction.

Note that #2/3c=(2c)/3#

#(cancel(3)^1xx-(2c)/cancel(3)^1)-(3xx7)=(3xx-9)#

#rArr-2c-21=-27larrcolor(red)" no fractions"#

add 21 to both sides.

#-2c cancel(-21)cancel(+21)=-27+21#

#rArr-2c=-6#

To solve for c, divide both sides by - 2

#(cancel(-2) c)/cancel(-2)=(-6)/(-2)#

#rArrc=3#

#color(blue)"As a check"#

Substitute this value into the left side and if it equals the right side then it is the solution.

#"left side "=(-2/3xx3)-7=-2-7=-9#

#rArrc=3" is the solution"#