[(42×5+670:2-15×3):5+812-(12×12+15×33)]×7

Răspuns :

[( 42 x 5 + 670 : 2 - 15 x 3 ) : 5 + 812 - ( 12 x 12 + 15 x 33 ) ] x 7 = 

= [ ( 210  + 335 - 45 ) : 5 + 812  - ( 144 + 495 ) ] x 7 

= [ ( 545 - 45 ) : 5 + 812 - 639 ] x 7 

= [ 500 : 5 + 812 - 639 ] x 7 

= [ 100 + 812 - 639 ]  x 7 

= [ 912 - 639 ] x 7 

= 273 x 7 

= 1911
[(210+335-45):5+812-(144+495)]x7=
(500:5+812-639)x7=
(100+812-639)x7=
273x7=1911