How do you solve #(3x - 7) - 5( x - 4) = 21#?

2 Answers
Mar 18, 2018

Answer:

x=-4

Explanation:

[0] #(3x-7)-5(x-4)=21#
First let's simplify by a product rule the term #5(x-4)#
[1] #(3x-7)-5*x-(5*-4)=21#
We also have #-a*-b=a*b#, so:
[2] #(3x-7)-5x+20=21#
Parenthesis on #(3x+7)# are useless, so we have :
[3] #3x-7-5x+20=21#
Let's put all numbers on the right part:
[4]#3x-7+7-5x+20-20=21+7-20#
[5]#-2x=8#
Finally let's Just divide by-2
[6]#x=-4#

Mar 18, 2018

Answer:

#x=-4#

Explanation:

We can start by distributing the #-5# to the #(x-4)# term. We get:

#3x-7-5x+20=21#

We can combine like terms to get:

#-2x+13=21#

We can subtract #13# from both sides to get:

#-2x=8#

Lastly, we can divide both sides by #-2# to get:

#x=-4#

Hope this helps!