51) 501.010- { [(7+X):4-3]×(9-2×4)}×501=500.509 prin metoda mersului invers

Răspuns:
Explicație pas cu pas:
501010-{[(7+X):4-3]x(9-2x4)}x501=500509
{[(7+X):4-3]x(9-2x4)}x501=501010-500509
{[(7+X):4-3x(9-2x4)}x501= 501
[(7+X):4-3x(9-2x4)]=501:501
(7+X):4-3x(9-2x4)=1
(7+X):4-3x(9-8)=1
(7+X):4-3x1=1
(7+X) :4-3=1:1
(7+X):4-3=1
7+X:4=3+1
7+X:4=4
7+X=4x4
7+X=16
X=16-7
X=9