How many coins do they have in all?
The general formula for the distance between two points is

Anyway, if A and B have the same x or y coordinates, this formula can be simplified. For example, in this case the two points have the same x coordinate of -8, so the following part of the formula simplifies:

So, we're left with

but the square root of a square is the absolute value of the object being squared:

which is this case means 
which is the correct length of the side.
Reflection across x axis and move 1 unit to the right
Hello,
y=x²-10x+7=x²-2*5x+25-25+7=(x-5)²-18
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Answer:

Step-by-step explanation:
Use the cosine ratio,
. Insert the values:

Isolate x. Multiply both sides by x:

Divide both sides by cos 25:

Insert into a calculator:

Round to the nearest hundredth:

Done.