How do you solve #7/5x+3/5= -x#?

1 Answer
Jul 1, 2015

Answer:

#x = -1/4#

Explanation:

#7/5.x+3/5=−x#

Let us write "#-x#" otherwise :

<=> #7/5.x+3/5=−5/5.x#

If we add the same value to each side, we maintain the equality :

<=> #7/5.x+3/5 color(red)+ color(red)(5/5.x)=−5/5.x color(red)+ color(red)(5/5.x)#

Add together fractions with a unknown & with the same denominator :

<=>#color(green)(7/5.x)+3/5 + color(green)(5/5.x)=0#

<=>#color(green)(12/5.x)+3/5=0#

Substract -3/5 to each member of equality :

<=>#12/5.x=-3/5#

Multiply by 5 each side :

<=>#12x = -3#

<=>#x = -3/12#

<=>#x = -1/4#

Note : You can start with a multiplication :

#7/5.x+3/5=−x# <=> #7x+3=−5x#
but I like to complicate my life. ;)