Could someone fill this all in for me? It's for 7th grade math so it shouldn't be too hard.

4+6x-3x^3 in standard form with explanations because i don’t understand

In the proof of the triangle angle sum theorem, you must draw an auxiliary line. which construction must you use to draw this line?

Triangle jkl was dilated using the rule dm, 1/3 the image, triangle j’ k’ l’ is the result of the dilation. a.5 units b.7.5 units c.10 units d.12.5 units