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{9×7+3×[(a×6:4):2]+2×5}:10+2×19=48​

Răspuns :

Răspuns: a=12

Explicație pas cu pas:

{9×7+3×[(a×6÷4)÷2]+2×5}÷10+2×19=48

{63+3×[(a×6÷4)÷2]+10}÷10+38=48

{63+3×[(a×6÷4)÷2]+10}÷10=48-38

{63+3×[(a×6÷4)÷2]+10}÷10=10

63+3×[(a×6÷4)÷2]+10=10×10

63+3×[(a×6÷4)÷2]+10=100

63+3×[(a×6÷4)÷2]=100-10

63+3×[(a×6÷4)÷2]=90

3×[(a×6÷4)÷2]=90-63

3×[(a×6÷4)÷2]=27

(a×6÷4)÷2=27÷3

(a×6÷4)÷2=9

a×6÷4=9×2

a×6÷4=18

a×6=18×4

a×6=72

a=72÷6

a=12

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verificare

{9×7+3×[(12×6÷4)÷2]+2×5}÷10+2×19=

=48

{63+3×[(72÷4)÷2]+10}÷10+38=48

[63+3×(18÷2)+10]÷10+38=48

(63+3×9+10)÷10+38=48

(63+27+10)÷10+38=48

(90+10)÷10+38=48

100÷10+38=48

10+38=48

Răspuns:  a = 12

Explicație pas cu pas:

{9 ×7 + 3 × [( a × 6 : 4 ) : 2] + 2 × 5 } : 10 + 2 × 19 = 48​

{63 + 3 × [(a × 6 : 4 ) : 2 ] + 10 } : 10 + 38 = 48

{63 + 3 × [(a × 6 : 4 ) : 2 ] + 10 } : 10 = 48 - 38

{63 + 3 × [(a × 6 : 4 ) : 2 ] + 10 } : 10 = 10

63 + 3 × [(a × 6 : 4 ) : 2 ] + 10 = 10 × 10 = 100

3 × [(a × 6 : 4 ) : 2 ] = 100 - 10 - 63

3 × [(a × 6 : 4 ) : 2 ] = 27

(a × 6 : 4 ) : 2 = 27 : 3

a × 6 : 4 = 9 × 2

a × 6 : 4 = 18

a = 18 × 4 : 6 → aplic metoda mersului invers

a = 72 : 6

a = 12