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
1 meter = 3 feet = 36 inches... so the answer would be B. 36 in
Um.. Both of those equations are the exact same. Divide both sides of the first equation by 6. You get:

That is the exact same as the second equation. This system has an infinite number of solutions. 5x - 7y = -1 is a line, so basically every point on that line is a solution to the system.
For example,

and

would work, but so would

and
Answer:
The Magazines each costed $8.30 and the books cost $13.80 for the amount of $41.50. and the 2 magazines and 5 books for $42.25 the 2 magazines is $21.12 for each and $8.45 for each book.
Step-by-step explanation:I got the answers by taking the total cost and taking the number of books or if it was a a magazine and I would divide it by lets just say you have 42.25 dollars you would divide that by 3 and you would do it for every item with the total cost.