Please help....find the domain of the function f(x)=sqrt(5x-20). Thank you

In how many ways can three cards be selected from a 52-card deck if the selected card is returned to the deck each[..]

Please help....Determine whether or not the function is one-to-one. f(x)=sqrt(11x-5). Thank you

Please help....Determine whether or not the function is one-to-one. f(x)=2x-7. Thank you

Can you please help me to find the domain of function. f(x)=1/x-12. Thank you...

Three coins are tossed. What is the probability that at least one tail will be turned up? Please help!

Please help me to find the domain of the function f(x)=sqrt(5x-20). Thanks

Can you please help me to find the inverse of the function if it exists. f(z)=sqrt(3z+12). Thank you

Can you please help me to find the inverse of the function if it exists. f(n)=5n^3-1. Thank you!

56,28,14,7... Find the 21st term of this sequence. Help please!