Perform the addition and simplify: tanx/cscx + sinx/tanx

What is the missing step in this proof ?

Which of the following values cannot be probabilities? 0.08, 5 divided by 3, startroot 2 endroot, negative 0.59, 1, 0, 1.44, 3 divided by 5 select all the values that cannot be probabilities. a. five thirds b. 1.44 c. 1 d. startroot 2 endroot e. three fifths f. 0.08 g. 0 h. negative 0.59

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25