How Do You Solve a Two-Step Equation by Combining Like Terms?

'x' is the variable we're solving for
Like terms are terms that contain the same variables raised to the same power
'-6x' and '3x' are like terms, so you can add their coefficients to get the coefficient of the new term
The coefficient of the new 'x' term is -3
If you divide one side by -3 you MUST divide the other side by -3 to keep the equation equal

1. 'x' is the variable we're solving for
2. Like terms are terms that contain the same variables raised to the same power
1. '-6x' and '3x' are like terms, so you can add their coefficients to get the coefficient of the new term
2. The coefficient is the number in front of the variable 'x'
3. So the coefficients here are -6 and 3
1. 'x' is the variable we're solving for
2. Since -6 + 3 = -3, -3 is the coefficient of the new 'x' term
1. We need to divide both sides of the equation by -3 to get 'x' by itself
1. The Division Property of Equality says that if you divide one side by a number, you need to divide the other side by the same number
2. Otherwise, the left and right sides of the equation would no longer be equal
1. The -3 cancels out on the left, leaving just 'x'
2. -21 divided by -3 gives us 7 on the right
1. To check the answer, plug it back into the original equation
1. If the equation is true after plugging in our answer, we know we've found the right answer
1. -21 = -21 is a true statement!
2. This means that our answer is correct!

Solve for x in the following equation: -6x + 3x = -21