Question 590
If x is the original price, then (since 30% is 0.3) we know that:

{{{x + (0.3)x = 104}}}

Multiply by 10 to get rid of decimals:

{{{10x + 3x = 1040}}}

{{{13x = 1040}}}

Divide by 13:

{{{x = 80}}}

The bike was originally bought for $80.