Question

Aflati numarul natural X astfel incat:
[(5÷X+3×5)÷4-4]+9=10
Va rog!dau 5 stele,inimioara si coroana PLESE

Answer 1

[(5:x+3x5):4-4]+9=10

[(5:x+3x5):4-4]=1

[(5:x+15):4-4]=1

[(5:x+15):4]=5

(5:x+15)=20

5:x=5

x=1

Answer 2

[ ( 5 : X + 3 × 5 ) : 4 - 4 ] + 9 = 10

( 5 : X + 15 ) : 4 - 4 = 10 - 9

( 5 : X + 15 ) : 4 = 1 + 4

5 : X + 15 = 5 × 4

5 : X + 15 = 20

5 : X = 20 - 15

5 : X = 5

X = 5 : 5

X = 1 → numarul, aflat prin metoda mersului invers

Verific:

[ ( 5 : 1  + 15 ) : 4 - 4 ] + 9 = 10

=[ ( 5 + 15 ) : 4 - 4 ] + 9 =

= ( 20 : 4 - 4) + 9

= ( 5 - 4 ) + 9 =

= 1 + 9 =

= 10