a) 45.37 + 45.63 – 100 b) 148.9 - 32.48 c) 307 - [(180.40 - 160) : 22 + 9] : 2 d) 12 + 3.{90 : [39 - (23 - 5)2]}

Giải thích các bước giải:

$\textit{a) 45.37+45.63-100}$

$\textit{= 45.(37+63)-100}$

$\textit{= 45.100-100}$

$\textit{= 4500-100}$

$\textit{= 4400}$

$\textit{b) 148.9-32.48}$

$\textit{= 1332-1536}$

$\textit{= -204}$

$\textit{c) 307-[(180.40-160):22+9]:2}$

$\textit{= 307-[(7200-160):22+9]:2}$

$\textit{= 307-[7040:22+9]:2}$

$\textit{= 307-[320+9]:2}$

$\textit{= 307-329:2}$

$\textit{= 307-164,5}$

$\textit{= 142,5}$

$\textit{d) 12+3.{90:[39-(23-5):2]}}$

$\textit{= 12+3.{90:[39-18:2]}}$

$\textit{= 12+3.{90:[39-9]}}$

$\textit{= 12+3.{90:30}}$

$\textit{= 12+3.3}$

$\textit{= 12+9}$

$\textit{= 21}$

$\textit{Chỗ (23-5)2 là số 52 hay là (23-5):2}$
$\textit{Nếu là số 52 thì bn kêu mik sửa ak}$
$\textit{Chớ đừng bc vội ak}$