Select the correct equation that represents an am signal. a. s(t) = ac[1 + μam cos (2πfmt)] cos (2πfct) b. s(t) = ac cos [2πfct + βfm *sin(2πfmt)] c. s(t) = ac cos [2πfct + μp cos (2πfmt)] d. c(t) = ac cos (2πfct ± φ)

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.

What adds to be the bottom number but also multiplies to be the top number with 8 on the bottom and 15 on top

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)}