If x+!x+!x+!x+=9, find x.

We know that x+!x+!x+!x+=9, so x+9=9. Squaring both sides we get x+9=81, so x=81-9=72.

jmc

algebra intermediate

Problem

x + x + x + x + \dots = 9

, find

x

Solution

We know that

x + x + x + x + \dots = 9

, so

x + 9 = 9

. Squaring both sides we get

x + 9 = 81

, so

x = 81 - 9 = 72

Final answer