Question

2. tính nhanh

11-12+13-14+15-16+17-18+19-20+21+22

Answer 1

  

Answer 2

2.

\(11-12+13-14+15-16+17-18+19-20+21-22\)(sửa đề)

\(=\left(11-12\right)+\left(13-14\right)+\left(15-16\right)+\left(17-18\right)+\left(19-20\right)+\left(21-22\right)\)

\(=-1+\left(-1\right)+\left(-1\right)+\left(-1\right)+\left(-1\right) +\left(-1\right)\)

\(=\left(-1\right)\cdot6\)

\(=-6\)