Chapter 9 · Questions · page 59 of 68
How do you distribute a negative sign?
Short answerMultiply every term inside by the negative number, which flips every sign inside. -2(x - 5) becomes -2x + 10.
levelPre-algebra
standard7.EE.A.1
practiceLike terms and distributing
A minus in front of parentheses is a -1 multiplying the whole group. Every term inside changes sign, including the last one, which is where most slips happen.
How to use it
- Treat a bare minus in front as -1.
- Multiply each term inside by the negative number.
- Check the last term: a minus inside becomes a plus.
Example
Where it goes wrong
- Flipping only the first sign: -(x - 4) is -x + 4, not -x - 4.
- Writing -2(x - 5) as -2x - 10.