The sum of the first 5 terms of an AP is 30 and the sum of the four term from T6 to T9 (inclusive) is 69. Find the AP

Atriangle has sides with lengths of 10 yards, 13 yards, and 18 yards. is it a right triangle?

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.

Ialready asked this but i never got an answer. will give a high rating and perhaps brainliest. choose the linear inequality that describes the graph. the gray area represents the shaded region. y ≤ –4x – 2 y > –4x – 2 y ≥ –4x – 2 y < 4x – 2