I WILL NAME BRAINLIEST (: 20 points (: Sorry you can't see it well, but it says: " Ian's mom sang him S songs. His sister sang him two times as many songs as his mom had. If Ian listened to nine songs in all, how many did his mom sing? Write an equation and solve.

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.

Extra points! find the missing dimension! need asap

Hich equation can pair with x + 2y = 5 to create an inconsistent system? 2x + 4y = 3 5x + 2y = 3 6x + 12y = 30 3x + 4y = 8