Question

Which equation has the solution x = 3?

Answer 1

Well, let's first solve each equation:

1.) -4x + 6 - 3x = 12 - 2x - 3x

To start, combine each like-term on each side of the equal sign (The numbers with variables in-common // the numbers alike on the same side of the equal sign):

-7x + 6 = 12 - 5x

Now, we get the two terms with variables attached to them, on the same side, so, we do the opposite of subtraction, which is, addition:

-7x + 6 = 12 - 5x
+5x +5x
_____________
-2x + 6 = 12

Next, you do the opposite of addition, which is, subtraction, and, subtract 6 from both sides:

-2x + 6 = 12
-6 -6
____________
-2x = 6

Finally, divide by -2 on each side, to find out what the value of 'x' is:

-2x = 6
÷-2 ÷-2
________
x = -3

So, the answer is not 'A.'
_________________________________________

Now, we test out the rest of the equations, the exact same way:

2.) 4x + 6 + 3x = 12 + 2x + 3x

Combine your like-terms, on each side of the equal sign:

7x + 6 = 12 + 5x

Now, get both terms, with the variable, 'x,' to the same side, and, to do that, do the opposite of addition, which is, subtraction:

7x + 6 = 12 + 5x
-5x -5x
______________
2x + 6 = 12

Next, subtract 6 from both sides:

2x + 6 = 12
-6 -6
__________
2x = 6

Finally, divide by 2, on both sides:

2x = 6
÷2 ÷2
__________
x = 3

So, the answer is 'B.'
_________________________________________

3.) 4x + 6 - 3x = 12 - 2x - 3x

Again, we combine the like-terms, on both sides of the equal sign:

x + 6 = 12 - 5x

Now, we get both terms with the variable 'x,' to the same side, and, the opposite of subtraction, is addition, so, we're going to add 5x to both sides:

x + 6 = 12 - 5x
+ 5x + 5x
______________
6x + 6 = 12

Now, we subtract 6 from each side, because, the opposite of addition, is subtraction:

6x + 6 = 12
- 6 - 6
_____________
6x = 6

Now, divide by 6, on both sides:

6x = 6
÷ 6 ÷ 6
_____________
x = 1

So, the answer is not 'C.'
_________________________________________

4.) 4x + 6 - 3x = 12x + 2x + 3x

First, we combine the like-terms:

x + 6 = 17x

Next, we get both terms, with the variable, 'x,' to the same side:

x + 6 = 17x
-x -x
_____________
6 = 16x

Now, divide by 16, on both sides:

X = 3/8

So, 'D,' is not the answer.
_______________________

The answer is, 'B.'

I hope this helps!