Question

8．規(guī)定新運(yùn)算$|\begin{array}{l}{a}&\\{c}&08pcewt\end{array}|$=a×d-b×c，那么$|\begin{array}{l}{2}&{1}\\{3}&{4}\end{array}|$=5．

Answer 1

分析 根據(jù)定義新運(yùn)算，知道$|\begin{array}{l}{a}&\\{c}&drn9xfs\end{array}|$=a×d-b×c，把a(bǔ)=2，b=1，c=3，d=4代入計(jì)算即可求出$|\begin{array}{l}{2}&{1}\\{3}&{4}\end{array}|$的值．

解答 解：$|\begin{array}{l}{2}&{1}\\{3}&{4}\end{array}|$=2×4-1×3=8-3=5．
故答案為：5．

點(diǎn)評(píng) 解答此題的關(guān)鍵是，根據(jù)所給出的式子，得出新的運(yùn)算方法，再利用新的運(yùn)算方法解決問(wèn)題．