13x{602-3x[a+7x(8x5-15)]}=50. ajutatima va rog


Răspuns :

13x{602-3x[a+7x(8x5-15)]}=50

13x{602-3x[a+7x(40-15)]}=50

13x[602-3x(a+7x25)]=50

13x[602-3x(a+175)]=50

13x(602-3a-525)=50

13x(77-3a)=50

1001-39a=50

39a=1001-50

39a=951

a=951/39

a=317/13