(127 + x) − 236 = 418
127 + x = 418 + 236
127 + x = 654
x = 654 − 127
x = 527
Ответ: 527

Вычисления:
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}418\\ 236\end{array}}\\ \begin{array}{r}\mathrm{654 }\end{array}\end{array}$
 
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}654\\ 127\end{array}}\\ \begin{array}{r}\mathrm{527 }\end{array}\end{array}$

(y − 246) + 154 = 300
y − 246 = 300 − 154
y − 246 = 146
y = 146 + 246
y = 392
Ответ: 392

Вычисления:
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}300\\ 154\end{array}}\\ \begin{array}{r}\mathrm{146 }\end{array}\end{array}$
 
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}146\\ 246\end{array}}\\ \begin{array}{r}\mathrm{392 }\end{array}\end{array}$

(492 − a) − 87 = 245
492 − a = 245 + 87
492 − a = 332
a = 492 − 332
a = 160
Ответ: 160

Вычисления:
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}245\\ 87\end{array}}\\ \begin{array}{r}\mathrm{332 }\end{array}\end{array}$
 
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}492\\ 332\end{array}}\\ \begin{array}{r}\mathrm{160 }\end{array}\end{array}$

745 − (b − 358) = 455
b − 358 = 745 − 455
b − 358 = 290
b = 290 + 358
b = 648
Ответ: 648

Вычисления:
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}745\\ 455\end{array}}\\ \begin{array}{r}\mathrm{290 }\end{array}\end{array}$
 
$\begin{array}{r}\begin{array}{r}+\end{array}\underline{\begin{array}{r}290\\ 358\end{array}}\\ \begin{array}{r}\mathrm{648 }\end{array}\end{array}$

304 − (543 − m) = 266
543 − m = 304 − 266
543 − m = 38
m = 543 − 38
m = 505
Ответ: 505

Вычисления:
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}304\\ 266\end{array}}\\ \begin{array}{r}\mathrm{38 }\end{array}\end{array}$
 
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}543\\ 38\end{array}}\\ \begin{array}{r}\mathrm{505 }\end{array}\end{array}$

789 − (x + 162) = 519
x + 162 = 789 − 519
x + 162 = 270
x = 270 − 162
x = 108
Ответ: 108

Вычисления:
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}789\\ 519\end{array}}\\ \begin{array}{r}\mathrm{270 }\end{array}\end{array}$
 
$\begin{array}{r}\begin{array}{r}-\end{array}\underline{\begin{array}{r}270\\ 162\end{array}}\\ \begin{array}{r}\mathrm{108 }\end{array}\end{array}$