Question

Va rog sa ma ajutati!Am nevoie urgenta de rezolvări! Dau coroana!!! Calculati: a) 412:4-{12-2x[36-4x(9:a)] +5x12}:6=91. b) 1+{2+3x[4+5x(6-a)] :7}:8=2. c) 12+{12+[12-(12:a+5):3]:5}:7=14

Answer 1

412:4-{12-2x[36-4x(9:a)] +5x12}:6=91

103-{12-3×[36-4×(9:a)] + 60} : 6 = 91

{12-3×[36-4×(9:a)] + 60} : 6 = 103 - 91

{12-3×[36-4×(9:a)] + 60} : 6 = 12

12-3×[36-4×(9:a)] + 60 = 12 × 6 = 72

3×[36-4×(9:a)] = 72 - 60 - 12

3×[36-4×(9:a)] = 0

4 × (9:a) = 36

9 : a = 46 : 4

9 : a = 9

a = 1


b) 1+{2+3x[4+5x(6-a)] :7}:8=2

{2+3x[4+5x(6-a)] :7}:8=2-1 = 1

2+3x[4+5x(6-a)] :7 = 1 × 8 = 8

3x[4+5x(6-a)] :7 = 8 - 2 = 6

3×[4+5×(6-a)] = 6 × 7 = 42

4 + 5 ×(6-a) = 42 : 3 = 14

5 × ( 6 - a) = 14 - 4 = 10

6 - a = 10 : 5

6 - a = 2

a = 6 - 2

a = 4


c) 12+{12+[12-(12:a+5):3]:5}:7=14

{12+[12-(12:a+5):3]:5}:7=14 - 12 = 2

12+[12-(12:a+5):3]:5= 2×7 = 14

[12 - (12 : a + 5) : 3] : 5 = 14 - 12 = 2

12 - (12 : a + 5) : 3 = 2×5 = 10

(12 : a + 5) : 3 = 12 - 10 = 2

12 : a + 5 = 3×2 = 6

12 : a = 6 - 5 = 1

a = 12