How do you solve #2x-3+4x=21#?

2 Answers
Principal
Aug 20, 2017

Combine like terms, and solve for the missing variable.

Answer: #x=4#

Explanation:

Simply start out by combining like terms. That includes any variables with coefficients (numbers in front of the letters), and any other terms. In this case, we can combine #2x# and #4x# to make #6#, while #-3# stands alone as the only number on the left side of the equation. Now we have:

#6x-3=21#

The following step would be to add #3# to each side to cancel out the #-3# and to consolidate the variable.

#6x=24#

Now we simply divide by #6# to get the variable (which in this case is #x#) alone.

#6/6x=24/6#

These numbers divide evenly with each other to create a quotient such as #x=4#. Therefore, #x=4# is our answer. However let's plug #4# back into the equation to see if both sides check out.

#6(4)-3=21#

#6(4)=24#

#24-3=21#

Does #21=21#? Yes! So our verification checks out.

Answer: #4#

Jumbotron
Aug 20, 2017

#x = 4#

Explanation:

#2x - 3 + 4x = 21#

#6x - 3 = 21#

#6x = 21 + 3#

#6x = 24#

#x = 24/6#

#x = 4#

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