Twelve less than a number is the same as 6, decreased by 8 times the number. What is the number?

2 Answers
Oct 4, 2017

The number is #color(purple)2#

Explanation:

Let x be the number.
Equation is #x-12=6-8x#
#x+8x=6+12#
#9x=18#
#x=2#

Oct 4, 2017

#n=2# (see explanation)
The number is 2.

Explanation:

Let's make the number #n# (variable). We're going to solve for #n# later.

"Twelve less than a number" #n-12#
"is the same as 6" #=6...#
"decreased by 8 times the number" #-8n#

"Twelve less than a number is the same as 6, decreased by 8 times the number" #n-12=6-8n#


Ok, now we have to solve to find #n#...
First move everything with the variable to the left side.
#n\color(indianred)(+8n)-12=6\cancel(-8n)\cancel(\color(indianred)(+8n))#
#9n-12=6#

Now move all non-variable values to the right.
#9n\cancel(-12)\cancel(\color(slateblue)(+12))=6\color(slateblue)(+12)#
#9n=18#

Dividing to get the answer: #(\cancel(9)n)/\cancel(\color(seagreen)(9))=18/\color(seagreen)(9)#
#n=2#