27 + a - 15 = 19
27 + a = 19 + 15
27 + a = 34
a = 34 - 27
a = 7
27 + a = 19 + 15
27 + a = 34
a = 34 - 27
a = 7
27 + a - 15 = 19
27 + a = 19+15
27 + a = 34
a = 34-27
a = 7
27+a-15=19
27+a =19-15
27+a =34
a =34-27
a =7
27 + a - 15 = 19
27 + a = 19 -15
27 + a = 34
a = 34 - 27
a = 7
K cho mình nhé !
