Answer:
Step-by-step explanation:
Let's say the Physics book costs $x
The Chemistry book will cost $x - $6
Two such Chemistry books will cost;
2($x - $6) = $(2x - 12)
Three such Physics books cost $3x
$(2x - 12) + $3x = $123
$5x - $12 = $123
$5x = $111
x = $22
So the Physics book costs; $22
and the Chemistry book costs $22
- 6 = $16
Answer: The answer is A.
Step-by-step explanation:
Hello,

You have just to read the arrows un reversed order:
in f we find (-1,-3) so in f^{-1} we find (-1,-3)^{-1}=(-3,-1)
Answer:
Angle b
Step-by-step explanation: