Thực hiện phép tính (Tính nhanh nếu có thể)a) \(18...

A

- Hướng dẫn giải

Phương pháp giải:

Áp dụng các quy tắc:

- Thứ tự thực hiện các phép tính đối với biểu thức không có dấu ngoặc:

                        Lũy thừa \( \to \) Nhân và chia \( \to \) Cộng và trừ

- Thứ tự thực hiện các phép tính đối với biểu thức có dấu ngoặc: \((\,\,)\,\, \to {\rm{[}}\,\,{\rm{]}}\,\, \to {\rm{\{ }}\,\,{\rm{\} }}\) 

Giải chi tiết:

\(\begin{array}{l}a)\,18.25 + 75.18 - 1200\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,b)\,{6^7}:{6^5} + {3.3^2} - {2017^0}\\\,\,\,\, = 18.(25 + 75) - 1200\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \,\,\,{6^2} + {3^3} - 1\\\,\,\,\, = 18.100 - 1200\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \,\,36\, + 27 - 1\\\,\,\,\, = 1800 - 1200\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \,\,\,63 - 1\\\,\,\,\, = \,\,600\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \,\,\,\,62\,\,\,\\{\rm{c)}}\,{\rm{\{ [}}(20 - 2.3).5{\rm{]}} + 2 - 2.6\} \,\,:\,\,2\, + \,{(4.5)^2}\\\,\,\, = {\rm{\{ [}}(20 - 6).5{\rm{]}} + 2 - 12\} \,\,:\,\,2\, + \,{20^2}\\\,\,\, = {\rm{\{ [14}}.5{\rm{]}} + 2 - 12\} \,\,:\,\,2\, + \,400\\\,\,\, = \,{\rm{\{ 70 + 2}} - {\rm{12\} :}}\,\,{\rm{2  + }}\,\,{\rm{400}}\\\,\,\,{\rm{ = }}\,\,{\rm{(72}} - {\rm{12\} :}}\,\,{\rm{2  + }}\,\,{\rm{400}}\\\,\,\,{\rm{ = }}\,\,{\rm{60}}\,\,{\rm{:}}\,\,{\rm{2}}\,\,{\rm{ + }}\,\,{\rm{400}}\\\,\,\,{\rm{ =  30}}\,\,{\rm{ + }}\,\,{\rm{400}}\\\,\,\,{\rm{ =  430}}\end{array}\)

Chọn A.