a tennis player won 0.805 of the matches she played.what percent of the matches did she lose?

100(1.0 - 0.805) = ?

805%

To find the percentage of matches the tennis player lost, we can subtract the percentage of matches she won from 100%.

First, let's find the percentage of matches she won. Given that she won 0.805 (or 80.5%) of the matches, we can say:

Percentage of matches won = 80.5%

To find the percentage of matches lost, we can subtract the percentage of matches won from 100%:

Percentage of matches lost = 100% - 80.5%
= 19.5%

Therefore, the tennis player lost 19.5% of the matches she played.