Question

1215-[130+(11x3+15xa)]x5=250 COROANA,5 STELE,MULTUMESC,60 PUNCTE

Answer 1

Răspuns:  a = 2

Explicatie pas cu pas:

1 215 - [ 130 + ( 11 × 3 + 15 × a ) ] × 5 = 250

[ 130 + ( 33 + 15 × a) ] × 5 = 1 215 - 250

[ 130 + ( 33 + 15 × a) ] × 5 = 965

130 + ( 33 + 15 × a) = 965 : 5

130 + ( 33 + 15 × a) = 193

33 + 15 × a = 193 - 130

33 + 15 × a = 63

15 × a = 63 - 33

15 × a = 30

a = 30 : 15

a = 2 → numarul, aflat prin metoda mersului invers

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Verific:

1 215 - [ 130 + ( 33 + 15 × 2 )] × 5 =  250

= 1215 - ( 130 + 63) × 5 =

= 1 215 - 193 × 5  =

= 1 215 - 965 =

= 250