Răspuns:
Explicație pas cu pas:
1)a)
804 + 503 × 8 : 4 - 72 : 9 × 3 × 100 : 6 + 30 × 3 = 1 500
= 804 + 4 024 : 4 - 8 × 3 × 100 : 6 + 90 =
= 804 + 1 006 - 2400 : 6 + 90 =
= 1 810 - 400 + 90 =
= 1 410 + 90
= 1 500
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b)
100 - { 100 - [ ( 15 × 3 + 9) : 6 - 26 : 26 ] × 10 + 2 × 13 } × 2 = 8
= 100 - { 100 - [ ( 45 + 9 ) : 6 - 1 ] × 10 + 26 } × 2 =
= 100 - [ 100 - ( 54 : 6 - 1 ) × 10 + 26 ] × 2 =
= 100 - [ 100 - ( 9 - 1 ) × 10 + 26 ] × 2 =
= 100 - ( 100 - 8 × 10 + 26 ) × 2 =
= 100 - ( 100 - 80 + 26 ) × 2 =
= 100 - ( 20 + 26 ) × 2 =
= 100 - 46 × 2 =
= 100 - 92 =
= 8
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2)
100 - { 22 - 3 × [ 12 : ( 75 : a + 3 ) + 1 ] } × 5 = 35
{ 22 - 3 × [ 12 : ( 75 : a + 3 ) + 1 ] } × 5 = 100 - 35
{ 22 - 3 × [ 12 : ( 75 : a + 3 ) + 1 ] } × 5 = 65
22 - 3 × [ 12 : ( 75 : a + 3 ) + 1 ] = 65 : 5
22 - 3 × [ 12 : ( 75 : a + 3 ) + 1 ] = 13
3 × [ 12 : ( 75 : a + 3 ) + 1 ] = 22 - 13
3 × [ 12 : ( 75 : a + 3 ) + 1 ] = 9
12 : ( 75 : a + 3 ) + 1 = 9 : 3
12 : ( 75 : a + 3 ) + 1 = 3
12 : ( 75 : a + 3 ) = 3 - 1
12 : ( 75 : a + 3 ) = 2
75 : a + 3 = 12 : 2
75 : a + 3 = 6
75 : a = 6 - 3
75 : a = 3
a = 75 : 3
a = 25 → numarul, aflat prin metoda mersului invers
