A race is 20 miles long . There is water station every 1 1/4 miles along the race route. How many water stations are needed for this race ?

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.

3a + 5b - 7 = 0 a - 2b - 4 = 0 solve the system by the elimination method. check your work {(96/11, -5/11)} {(34/11, -5/11)} {(32/33, 5/11)}

How to express the radical using the imaginary unit , i.