How do you solve #\frac { 1} { 3} ( 90x - 12) = \frac { 1} { 2} ( 8x + 10)#?

1 Answer
Dec 28, 2016

#x = 9/26#

Explanation:

First, expand the terms in parenthesis on each side of the equation by multiplying each term in the parenthesis by the term outside the parenthesis:

#(color(red)(1/3) * 90x) - (color(red)(1/3) * 12) = (color(blue)(1/2) * 8x) + (color(blue)(1/2) * 10)#

#30x - 4 = 4x + 5#

Now we can add and subtract the necessary terms to isolate the #x# terms on one side of the equation and the constants on the other side of the equation while keeping the equation balanced:

#30x - 4 + color(red)(4) - color(blue)(4x) = 4x + 5 + color(red)(4) - color(blue)(4x)#

#30x - 0 - color(blue)(4x) = 4x - color(blue)(4x) + 9#

#30x - color(blue)(4x) = 0 + 9#

#30x - color(blue)(4x) = 9#

Next, we combine the #x# terms on the left side of the equation:

#(30 - 4)x = 9#

#26x = 9#

Finally, we solve for #x# while keeping the equation balanced by dividing each side of the equation by #color(red)(26)#:

#(26x)/color(red)(26) = (9)/color(red)(26)#

#(color(red)(cancel(color(black)(26)))x)/cancel(color(red)(26)) = (9)/color(red)(26)#

#x = 9/26#