Given:

To prove:

Proof:
In
,
because Given
because Given
because Reflexive property.
Corresponding sides of both triangles are congruent. So,
because SSS
Therefore, the required missing values are: Given,
, Reflexive property ,
, SSS respectively.
Part A: Chose some value for x, that means any amount of books to print for example 100 books, so x=100
Replace x=100 in C(x) and solve:
C(100)=3.5*100+1200=1550
Part B: Replace C(x) by 1900 and solve for x from the given equation:
1900=3.5x+1200
3.5x=1900-1200
x=700/3.5= 200
Part C: the statement C(20)=1270 means that 1270 is the cost for printing 20 books.
Part E: C(40.5)=1341.75 I think this statement is incorrect given the context because x means number of books to print so this value must be an integer number.
From the chord theorem we have:

Step-by-step explanation:
that's for Part B
Part C: triangles PQR and P"Q"R" are not congruent since the corresponding sides are not equal
Answer:
$600
Step-by-step explanation:
75*100/450
7500/450
600
<em>Thank me later :)</em>
(<em>Or just give brainliest)</em>