Question

Determina nr. natural x din egalitatea (x:(18-27:3)+51:17)×15=105.


Fara prea multe calcule odata va rog.

Answer 1

[ x : ( 18 - 27 : 3 ) + 51 : 17 ] · 15 = 105

x : ( 18 - 9 ) + 3 = 105 : 15

x : 9 + 3 = 7

x : 9 = 7 - 3

x : 9 = 4

x = 4 · 9

x = 36 → numarul aflat prin metoda mersului invers

Verificare:

[ 36 : ( 18 - 9 ) + 3 ] × 15 = ( 36 : 9 + 3 ) × 15 = ( 4 + 3 ) × 15 = 7 × 15 = 105

Answer 2

[x:(18-27:3)+51:17]×15=105
[x:(18-9)+3]×15=105
[x:9+3]×15=105
x:9+3=105:15
x:9+3=7
x:9=7-3
x:9=4
x=9×4
x=36

Proba :
[36:(18-27:3)+51:17]×15=105
[36:(18-9)+3]×15=105
(36:9+3)×15=105
(4+3)×15=105
7×15=105
105=105