This is a system of equations problem.
Blueberry = X, blackberry = Y
Joe:
5x + 10y = 135
James:
x + 9y = 104
Let’s isolate x from James’ equation.
x = 104 - 9y
Now substitute that into the first equation.
5(104 - 9y) + 10y = 135
520 - 45y + 10y = 135
-35y = -385
y = -385/-35. The negatives cancel out, leaving us with $11 for blackberries.
Now we can substitute that value into James’s equation.
x + 9(11) = 104
x = 104 - 99
x = $5
Final answer: Blueberry pies cost $5, blackberry pies cost $11.
I don't know what the graft is
First, we can choose the seats for the four mathematicians. Then we seat the physicits, then the engineer. There are 4! ways to seat the mathematicians, then 3! ways to seat the physicists, then 1! ways to seat the engineer. But then we must divide by 8, because we can rotate the table, so there are 8!*4!*3!/8 = 725760 ways to seat everyone.
Answer: The picture contains the answer and the steps
Answer:

Step-by-step explanation:
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