At the end of one performance the total that isaac received was 750. this included a tip for the usual fee of 649 what percent was the tip

Ok... he received 750 and the usual fee is 649. So the tip was 750-649=101.
Now we need to figure out what percentage of 649 Is 101.

649 × x = 101
649x = 101
x = 101/649
x = .1556

Multiply by 100 to convert to percentage.

x = 15.56% was the percent of tip.