Answer:
D.Transitive property of equality
Step-by-step explanation:
We are given that segment JK is parallel to segment LM
We have to prove 
We have to find which option correctly justifies the statement 4 of the two - column proof.
1.Statement : JK is parallel to segment LM
Reason: Given
2.
Reason: Vertical angles theorem
3.
Reason:Corresponding angles theorem
4.
Reason: Transitive property of equality.
If a=b and b=c then a=c
Hence, option D is true.
0.5s + 1 = 7 + 4.5s Subtract 4.5s from both sides
-4s + 1 = 7 Subtract 1 from both sides
-4s = 6 Divide both sides by -4
s = -

Simplify
s = -
<span>You need to set up 2 equations for this, a system to be exact
let x represent the cheaper phone and y represent the upgraded phone
for store costs you will have
5x+25y=200
for selling prices you will have 30x+100y=900
set these two equations together
5x+25y=200
30x+100y=900
multiply the first one by -4 and add them
-20x-100y=-800
30x+100y=900
10x=100
x=10
10 cheaper phones, plug into any equation again
5(10)+25(y)=200
y=6<<<6 upgraded phones</span>