The sum of triple a number and 6 is 9
3x+6=9Triple a number (3x) + 6subtract 6 from both sides3x=3Divide by 3 on both sidesX=1
We have an equation: 3?+ 6= 9⇒ 3?= 9-6⇒ 3*?= 3⇒ ?= 3/3⇒ ?= 1The number is 1~