Ta có: (5x+34).68=69.34
=> 5x + 34 = 69.34:68
=> 5x + 34 = 34.6 = 486
=> 5x = 486 : 34 = 6
=> x = 6:5 = 1,2
(5x+3^4).6^8 = 6^9.3^4
(5x+3^4) =6^9.3^4:6^8
5x+81 =486
5x =486-81
5x =405
x = 405:5
x =81
(5x+34)*68=69*34
5x+34=69*34/68
5x+34=69-8*34
5x+34=6*34
5x=6*34-34
5x=34*(6-1)
5x=34*5
x=34
x=81