Want to use a coordinate proof to prove that inidsegment de of aabc is parallel to ac and half
the length of ac which is the best first step?
vie
a place the triangle on a coordinate grid such that vertex a is at the origin, and ac lies
on the x-axis.
b. place the triangle on a coordinate grid such that bc lies on the x-axis and ab lies on
the s-axis
c. place the triangle on a coordinate grid such that vertex b is at the origin.
d. place the triangle on a coordinate grid such that vertex a is on the y-axis, and vertex
c is on the x-axis.

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.