afla termenul necunoscut: x+25 supra100= 58supra100; 100 supra 100 -x=25supra100 ; 75 supra100-x= 37 supra 100

(x + 25)/100 = 58/100

x + 25 = 58

x = 58 - 25

x = 33


sau
x + 25/100 = 58/100 |×100
100x + 25 = 58
100x = 58-25
100x = 33
x = 33/100


100/100 - x = 25/100 |×100

100 - 100x = 25

100x = 100 - 25

100x = 75

x = 75/100

x = 3/4


75/100 - x = 37/100 |×100

75 - 100x = 37

100x = 75 - 37

100x = 38

x = 38/100

x = 19/50