Răspuns:
5×[675-4×(300-10×23+59)]-777=499×9-399×9-98×9
5×[675-4×(300-230+59)]-777=499×9-399×9-98×9
5×[675-4×(70+59)]-777=9(499-399-98)
5×(675-4×129)-777=9(100-98)
5×(675-516)-777=9(100-98)
5×(675-516)-777=9(100-98)
5x158-777=9x2
795-777=18
18=18 (A)
Explicație pas cu pas: