Chapter 9 · Questions · page 60 of 68
How do you solve a two-step equation?
Short answerUndo the addition or subtraction first, then undo the multiplication or division. For 4x - 7 = 13, add 7 to get 4x = 20, then divide by 4 to get x = 5.
levelPre-algebra
standard7.EE.B.4a
practiceOne- and two-step equations
An equation like 4x - 7 = 13 was built by multiplying x by 4 and then subtracting 7. To get back to x you undo those in reverse order. Whatever you do to one side, you do to the other.
How to use it
- Add or subtract on both sides to clear the number that is added or subtracted.
- Multiply or divide both sides to clear the coefficient.
- Substitute your answer back in to check.
Example
Where it goes wrong
- Dividing first and only dividing part of the side.
- Losing the negative when dividing by a negative coefficient.