How do you solve #5x + 4x + 7 = x + 15#?

2 Answers
May 29, 2018

Answer:

Combine like terms and rearrange to solve for #x#. You will find that #x=1#

Explanation:

First, combine like terms on the Left Hand Side (LHS):

#5x+4x+7=x+15#

#x(5+4)+7=x+15#

#9x+7=x+15#

Next, we'll subtract 7 from both sides, which effectively moves the 7 to the Right Hand Side (RHS), and we will also subtract #x# from both sides, moving all #x#-related terms to the LHS:

#9xcancel(+7)color(red)(cancel(-7))color(blue)(-x)=cancel(x)+15color(red)(-7)color(blue)(cancel(-x))#

#9xcolor(blue)(-x)=15color(red)(-7)#

#8x=8#

Finally, divide both sides by #x#'s coefficient (8):

#(cancel(8)x)/color(red)(cancel(8))=8/color(red)(8)#

#color(green)(x=1#

May 29, 2018

Answer:

#x=1#

Explanation:

#5x + 4x + 7 = x + 15#

#5x + 4x -x= 15 -7#

#8x = 8#

#x=1#