Before you begin, familiarize yourself and keep in mind the order of operations- PEMDAS (parenthesis, exponents, multiplication, division, addition, subtraction). You must do all math problems using this.
17. Add all the numerators since they are like-terms. 12/3 – then simplify it – 4.
18. Do the inner most parenthesis first, add the numerators – 3/5. To multiply a fraction and a whole number, multiply the numerator and the whole number, and then simplify – 15/5, 3, then divide 15 by 3 – and your answer is 5.
19. Parenthesis first – 10/6. Then multiply the numerator and the whole number and simplify – 120/6 – 20.
20. Parenthesis – 4.2 – multiply by 8 – 33.6.
21. Parenthesis – 4 – multiply by 3.6 – 14.4.
22. PEMDAS, so division goes before subtraction – 8.4.
Try the rest for yourself; that’s the only way you’ll learn. Feel free to message me for more help.