Giải thích các bước giải:
$\text{Bài 1:}$
$a)189+2x=237$
$⇔2x=237-189$
$⇔2x=48$
$⇔x=24$
$\text{Vậy $x=24$}$
$b)(x-36):18=12$
$⇔x-36=12×18$
$⇔x-36=216$
$⇔x=216+36$
$⇔x=252$
$\text{Vậy $x=252$}$
$c)x-36:18=12$
$⇔x-2=12$
$⇔x=12+2$
$⇔x=14$
$\text{Vậy $x=14$}$
$d)6x-5=613$
$⇔6x=613+5$
$⇔6x=618$
$⇔x=103$
$\text{Vậy $x=103$}$
$e)315+2(146-x)=401$
$⇔315+292-2x=401$
$⇔607-2x=401$
$⇔-2x=401-607$
$⇔-2x=-206$
$⇔x=103$
$\text{Vậy $x=103$}$
$\text{Bài 2:}$
$a)38+41+159+62$
$=(38+62)+(41+159)$
$=100+200$
$=300$
$b)54.85+85.46-234$
$=85(54+46)-234$
$=85.100-234$
$=8500-234$
$=8266$
$c)74.37-37.54+156$
$=37(74-54)+156$
$=740+156$
$=896$
$d)42.53+47.156-47.114$
$=42.53+(47[156-114])$
$=42.53+47.42$
$=42(53+47)$
$=42.100$
$=4200$
$e)(98.7676-9898.76):2020$
$=(98.76.101-98.101.76):2020$
$=0:2020$
$=0$
Học tốt!!!
