Question

Calculati
12+{2×[32+(a-24)×5]:4}×3=75

Answer 1

12 + { 2 × [ 32 + ( a - 24 ) × 5 ] : 4 } × 3 = 75

{ 2 × [ 32 + ( a - 24 ) × 5 ] : 4 } × 3 = 75 - 12

{ 2 × [ 32 + ( a - 24 ) × 5 ] : 4 } × 3 = 63

2 × [ 32 + ( a - 24 ) × 5 ] : 4 = 63 : 3

2 × [ 32 + ( a - 24 ) × 5 ] : 4 = 21

2 × [ 32 + ( a - 24 ) × 5 ] = 21 × 4

2 × [ 32 + ( a - 24 ) × 5 ] = 84

32 + ( a - 24 ) × 5  = 84 : 2

32 + ( a - 24 ) × 5  = 42

( a - 24 ) × 5  = 42 - 32

( a - 24 ) × 5  = 10

a - 24 = 10 : 5

a - 24 = 2

a = 2 + 24

a = 26 → numarul, aflat prin metoda mersului invers