Question

(42:7×7-2):4×10=(5×7+5):8+9×10+a 2)(1+1×7+1×10):(40:8+4):a=45:5:(3×3). 3)(29+47-2×3):(1+2×3)=(7×8-4×4):a​

Answer 1

Răspuns:

Explicație pas cu pas:

( 42 : 7 × 7 - 2 ) : 4 × 10 = ( 5 × 7 + 5 ) : 8 + 9 × 10 + a

( 6 × 7 - 2 ) : 4 × 10 = (35 + 5) : 8 + 90 + a

(42 - 2 ) : 4 × 10 = 40 : 8 + 90 + a

40 : 4 × 10 = 5 + 90 + a

10 × 10 = 95 + a

100 = 95 + a

a = 100 - 95

a = 5 → numarul, aflat prin metoda mersului invers

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2)

( 1 + 1 × 7 + 1 × 10 ) : ( 40 : 8 + 4 ) : a = 45 : 5 : ( 3 × 3 )

( 1 + 7 + 10) : ( 5 + 4 ) : a = 9 : 9

18 : 9 : a = 1

2 : a = 1

a = 2 : 1

a = 2

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3)

( 29 + 47 - 2 × 3 ) : ( 1 + 2 × 3 ) = ( 7 × 8 - 4 × 4 ) : a

( 76 - 6 ) : ( 1 + 6 ) = ( 56 - 16 ) : a

70 : 7 = 40 : a

10 = 40 : a

a = 40 : 10

a = 4 → numarul