Can someone tell me what 5/6 x 9/10 is and explain it please don’t just give me a answer

Which is a true statement about an exterior angle of a triangle a. it is formed by two segments that are not sides of the triangle, b. it forms a linear pair with one of the interior angles of the triangle, c. it is complementary to one of the interior angles of the triangle. d. it is formed by two segments that are sides of the triangle.

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36