The sum of 15 and a number all divided by 2

If x + 10 = 70, what is x? a. 40 b. 50 c. 60 d. 70 e. 80

Factor the monomial completely 42a3b3

In the figure below, ∠dec ≅ ∠dce, ∠b ≅ ∠f, and segment df is congruent to segment bd. point c is the point of intersection between segment ag and segment bd, while point e is the point of intersection between segment ag and segment df. the figure shows a polygon comprised of three triangles, abc, dec, and gfe. prove δabc ≅ δgfe.