Question

FIȘĂ DE LUCRU
1. Calculează, respectând ordinea operatiilor:
a) 804 + 503.8:4-72:9.3 • 100: 6 + 30. 3 =
b)
100 - { 100 - [( 15 • 3 +9): 6 - 26:26 ] • 10+ 2.13} • 2 =
2. Determină valoarea lui ,,a" din egalitatea:
100 - { 22 - 3 •[ 12:(75:a + 3) + 1]}.5 = 35
repede va rog! Dau coroana! ​

Answer 1

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