Atextbook that janelle needs for her psychology class cost $199 plus 7% sales tax .which of the following questions correctly calculate the final cost c for the textbook after taxes

First you need to find what the tax is. TO do that multiply .7 by 199 to get 139.3 That means the tax is 139.3 dollars and you need to add it to the book cost for the finall answer. 199+ 139.30 = $338.3