Answer:
21.42x+28.56
Step-by-step explanation:
Expand: 4.2×5.1×x+4.2×6.8
4.2×5.1×x to (21.42)x
Simplify: 21.42x+4.2×6.8
4.2×6.8 = 28.5628.56
21.42x+28.56
10 books cost $30. To figure it out, it's just 3 times the number of books. XD
Answer:
Well, I'm not sure what you mean but Ptolemy's Theorem gives a relationship between the side lengths and the diagonals of a cyclic quadrilateral; it is the equality case of Ptolemy's Inequality. Ptolemy's Theorem frequently shows up as an intermediate step in problems involving inscribed figures.
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<em>-</em><em> </em><em>BRAINLIEST</em><em> answerer</em>