(3x + 5)(3x – 6) 18x – 6 9x² – 3x - 30 9x? 334 – 30 6x - 1
1 answer:
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The differnce of 2 perfect cubes
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a³-b³=(a-b)(a²+ab+b²)
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a³-b³=(a-b)(a²+ab+b²)
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Answer:
720°, 2340°, 180°
Step-by-step explanation:
Look at the attached image of a regular hexagon. I drew all possible lines from a vertex to other vertices (AC, AD, AE). Drawing in all those diagonals splits the hexagon into 4 triangles, and adding up the measures of all the triangle angles would account for all the interior angles of the hexagon.
♦ Four triangles have an angle sum of 180° x 4 = 720° (180° in each triangle).
See attached image2 to see what happens in an octagon. There are six triangles formed, so the total of all interior angle measures is 6 x 180° = 1080°.
What about a 15-sided regular polygon? How many triangles would be formed by putting in all the diagonals coming from one vertex? There will be 2 fewer triangles than the number of vertices, 13.
♦ The total of interior angle measures in a 15-gon is 13(180°) = 2340°
♦ A polygon with 3 sides is a single triangle; interior angle sum = 180°
