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3x - 4 + 4x = 24

how do I solve this equation?

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Marina A. | Tutoring in English, Business, and Law -all agesTutoring in English, Business, and Law -...
First add all the (x)s together on one side of the equation.  So 3x +4x is 7x
Now the problem becomes 7x -4 = 24 or -4 +7x = 24
Either way is fine.
7x -4 = 24 you need to get the x alone on one side away from the number -4 so you add 4 to each side of the = sign.
If you add +4 to -4 you get 0 so the 4 goes away, but you can't add 4 to one side unless you add 4 to the other so the problem becomes:
7x = 28 (because you added the 4 to the left side of the = sign and the right side of the = sign)
7x = 28 (now to take the 7 off of the x, you need to do the same thing to each side, but this time you divide to make the x be by itself.) 7x divided by 7 = 1x so divide 28 by 7 too and you get 4.
Just remember what you do to one side (add, subtract, divide, etc.) to make the x alone, you need to do to whatever is on the other side.
Laura D. | Math, reading and study skills are a method for success in life!Math, reading and study skills are a met...


Here we go: first always write out the equation. Always show all your work and you will make less mistakes.

3x - 4 + 4x = 24

Combine like variables and isolate any single numbers. Remember these equations are like a scale. What you do to one side, you do to the other. Always do the opposite of any operation on the left side and continue the same to the right, remember a scale or balance.

3x + 4x -4 = 24

7x -4 = 24

7x -4 + 4 = 24 + 4

7x  =  28

Isolate X

7x/7 =28/7

x = 4

Sarah D. | Accounting and prior special needs tutorAccounting and prior special needs tutor

THe first thing you do is figure out the parts that can be combined.  In this case you are able to add 3x and 4 x to get 7 x.


Now you are able to isolate the "x" by adding 4 to each side : 7x-4+4=24+4


The last part to figure out what x equals and to solve the equation is to divide both sides by 7: