Question

Grupati termenii,apoi efectuati rapid adunarile, dupa model:Model:4+3+7+16=(4+16)+(3+7)=20+10=30.:3+17+3+27;1+29+4+3;18+12+5+5;2+8+3+4+7;11+12+19+28;7+9+13+21;21+13+9+7;32+8+4+16;23+7+9+41.​

Answer 1

Răspuns:

Explicație pas cu pas:

Answer 2

3 + 17 + 3 + 27 = ( 3+17) + (3+27) = 20 + 30 = 50

1 + 29 + 4 + 3 = (1+29) + (4+3) = 30 + 7 = 37

18 + 12 + 5 + 5 = (18+12) + (5+5) = 30 + 10 = 40

2 + 8 + 3 + 4 + 7 = ( 2+8) + ( 3+7) + 4 = 10 + 10 + 4 = 24

11 + 12 + 19 + 28 = ( 11+19) + ( 12+28) = 30 + 40 = 70

7 + 9 + 13 + 21 = ( 7+13) + ( 9 + 21) = 20 + 30 = 50

21 + 13 + 9 + 7 = (21+9) + (13+7) = 30 + 20 = 50

32 + 8 + 4 + 16 = ( 32+8) + (4+16) = 40 + 20 = 60

23 + 7 + 9 + 41 = (23+7) + ( 9 + 41 ) = 30 + 50 = 80