Răspuns:
[tex]1 550 - [390 - (45 * 3 + 5* n)] * 5 = 750\\\\1 550 - [390 - 135 - 5* n)] * 5 = 750\\\\1 550 - 390*5 + 135*5 + 5*5* n= 750\\\\1550-1950+675+25n=750\\\\275+25n = 750\\\\25n= 750-275\\\\25n = 475\\\\n = 475:25\\\\\boxed{n=19}[/tex]
[tex](814 - 810) * c : [(8 + 8:8 * 32) - 30] - 28 = 50\\\\4c : ((8 + 1*32)-30) = 50 +28\\\\4c : (40-30) = 78\\\\4c : 10 = 78\\\\4c = 78*10\\\\4c = 780\\\\c = 780 : 4\\\\\boxed{c=195}[/tex]
[tex]19 * 25 + 2 * [9 *5+2 *(y - 149 * 2)] = 973\\\\475 + 2*(45 +2*(y-298)) = 973\\\\2*(45 +2y-2*298) = 973-475\\\\90+4y-2*596 = 498\\\\4y - 1192 = 498-90\\\\4y = 408+1192\\\\4y = 1600\\\\y = 1600 : 4\\\\\boxed{y = 400}[/tex]
[tex]((9* z + 12 356:4): 2 - 307): 10:5 - 2 * 5 = 17\\\\((9* z + 3089): 2 - 307): 2 - 10 = 17\\\\((9* z + 3089): 2 - 307): 2 = 17+10\\\\(9* z + 3089): 2 - 307 = 27 * 2\\\\(9z+ 3089): 2 = 54 + 307\\\\9z+ 3089 = 361 * 2\\\\9z = 722 - 3089 \: IESE \:\: NEGATIV[/tex]
[tex]12 + {12 + (12 - (12: x + 5): 3]: 5} : 7 = 14\\\\{12 + (12 - (12: x + 5): 3]: 5} : 7 = 14 - 12\\\\{12 + [12 - (12: x + 5): 3]: 5} : 7 = 2\\\\12 + [12 - (12: x + 5): 3]: 5 = 2 * 7\\\\12 + [12 - (12: x + 5): 3]: 5 = 14\\\\(12-(12: x + 5): 3): 5 = 14-12\\\\(12 - (12: x + 5): 3): 5 = 2\\\\12-(12: x + 5): 3 = 10\\\\12*3-12 : x - 5 = 30\\\\36 - 12: x - 5 = 30\\\\36 -12:x = 35\\\\36 = 35 +12:x\\\\36 - 35 = 12 : x\\\\1 = 12:x\\\\x = 12 * 1\\\\\boxed{x=12}[/tex]
