Răspuns :
x- nr. necunoscut
n*7-(3*9)=29 =(82:53=1,rest 29)
n*7-27=29
n*7=27+29
n*7=56
n=56:7
n=8
n*7-(3*9)=29 =(82:53=1,rest 29)
n*7-27=29
n*7=27+29
n*7=56
n=56:7
n=8