ax5+a = 360 :6

6xa = 60

a = 60 :6 

a = 10

a x 5 + a=360

a x( 5+1)=360

a x 6=360

a=360:6

a=60

a x 5 + a = 360 

a x 5 + a x 1 = 360

a x (5 + 1) = 360
a x 6 = 360
 a = 360 : 6
=> a = 60

aX5+aX1=360
aX(5+1)=360
aX6=360
a = 360:6
a = 60
Vậy a = 60