If a+b+c=0 then prove that
\frac { 1 } { 1 + x ^ { a } + x ^ { - b } } + \frac { 1 } { 1 + x ^ { b } + x ^ { - c } } + \frac { 1 } { 1 + x ^ { c } + x ^ { - a } } = 1l

Thelime contains the point(-3,0) and parallel x-3y=3( show all work)

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

The graph shows the charges for a health club in a month. make a function table for the input-output values. writes an equation that can be used to find the total charge y for the number of x classes