Change the decimal to a fraction: 0.123123123….

A. 123/999
B. 1 23/100
C. This decimal is Irrational and cannot be written as a fraction
D. 12 13/10
E. 123/1000

To convert the decimal 0.123123123... to a fraction, we can assign it the variable x and subtract it from 10x:

x = 0.123123123...
10x = 1.231231231...

Now we can subtract the first equation from the second equation to eliminate the repeating decimal:

10x - x = 1.231231231... - 0.123123123...
9x = 1.108108108...

Simplifying both sides of the equation:

9x = 1 + 0.108108108...
9x = 1.108108108...

To get rid of the decimal in 0.108108108..., we can assign it the variable y and subtract it from 10y:

y = 0.108108108...
10y = 1.081081081...

Again, we can subtract the first equation from the second equation:

10y - y = 1.081081081... - 0.108108108...
9y = 0.972972972...

Simplifying both sides of the equation:

9y = 0.972972972...
9y = 0.972972972...

Now we can solve for y:

9y = 0.972972972...
y = 0.972972972... / 9
y = 0.108108108...

Since y is equal to 0.108108108..., and we assigned the original repeating decimal x to be equal to this value, we can substitute y back into the equation for x:

9x = 1 + y
9x = 1 + 0.108108108...
9x = 1.108108108...

Now we can solve for x:

9x = 1.108108108...
x = 1.108108108... / 9
x = 0.123123123...

Therefore, the decimal 0.123123123... can be written as the fraction 123/999.

A. 123/999 is the correct answer.