[364 :7:(128×5 - 124 ×3 - a)] ×45-23 ×13 =286


Răspuns :

[52:(640-372-a)]x45-299=286

[52:(268-a)]x45=

=286+299=

=585

52:(268-a)=

585:45=13

268-a

52:13=

=4

268-a=

=4

a=268-4=

=264