A, because anything with a dilation will not be congruent as the original PQR :))
ANSWER:
a) y = 15x + 75
b) 50 weeks
EXPLANATION:
P A R T A
2 weeks, 105 dollars --> (2, 105)
5 weeks, 150 dollars --> (5, 150)
<u />
<u>if we use slope intercept form (y=mx+b), we must:</u>
1) find the slope
y2 - y1 -->> 150 - 105 = 45
x2 - x1 -->> 5 - 2 = 3
45/3 = 15
2) find the y intercept
y = 15x + b -->> 150 = 15 (5) + b -->> 150 = 75 + b -->> 75 = b
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P A R T B
y = 15x + 75 (substitute the y with 825 because that is the goal)
825 = 15x + 75 (solve normally)
750 = 15x
50 = x
Angle b will be 34 degrees because angle b and the other angle that is 34 degrees are vertical angles!
Let:
x = Chemistry textbooks sold
y = Physics textbooks sold
The textbook store sold a combined total of 260, so:

The number of chemistry books sold was three times the number of physics textbooks sold, so:

Let:

Replace (2) into (1):

Replace the value of y into (2):