That is way too much questions for one sitting. If you really struggle that much, download this app called photomath. You take a picture of one of the questions and then it instantly solves it and shows the work so you know how to do it.
For 16-25 however, you would need to rewrite your questions on a blank piece of paper with the variables substituted in. So let's say:
a + b² - (c-2).
You would need to rewrite it as the following in order for the app to solve it.
12 + 9² - (4 -2)