82.
Simplify

How to solve

81.
Simplify

How to solve

80.
Simplify

How to solve

79.
Simplify

How to solve

78.
Prove that given that where

How to solve

77.
Prove that

How to solve

76.
Express in terms of given that where , and

How to solve

75.
Express in terms of , and given that , and where

How to solve

74.
Express in terms of and given that and

How to solve

73.
Express in terms of and given that and

How to solve