4 books for 1$12.00 3 books for $9.00 What is the price per book? What is the constant of proportionality

Ihave this math question 2/3 ÷2 1/10=

Which statement explains how you could use coordinate geometry to prove that quadrilateral abcd is a parallelogram? -5 -4 -3 -2 -1 t 1 2 3 4 prove that all sides are congruent and have slopes that are opposite reciprocals prove that segments ad and ab are congruent and parallel prove that opposite sides are congruent and have equal slopes prove that segments bc and cd are congruent and parallel

Which graph has a rate of change of zero