Identify the terms, like terms, coefficients, and constants in each expression.
20. n + 4n - 7n - 1
21. -3d + 8 - d - 2
22. 5x + 4 + 9x
23. 2 + 3d + d
24. -3r + 7 - 3r - 12
PLS HELP 31 POINTS AND PLS DON'T GIVE WRONG ANSWERS PLSSSS HELP!!!