There must be more students in the class, and most of the class must have scored lower then Paul and his friends. I could be wrong, but I hope this helps! :D
The first reaction represented is a decomposition reaction due to the fact the bonded pair are being split apart.
The second equation is a single displacement because the B and C have switched places, which is the only change making it a single displacement. If there had been another bond and A had also moved, it would be double.
Answer:
B) 4x^2y^2
Step-by-step explanation:
8x^3y^2+20x^2y^4
4(2x^3y^2+5x^2y^4)
4x^2(2xy^2+5y^4)
4x^2y^2(2x+5y^2)
So the answer is B
Let x be your first alloy
2/5x+7/10(30-x)=1/2(30)
4x+210-7x=150
3x=60
x=20
So, you need 20 lbs of the first alloy, and 10 parts of the second to make 30 lbs of half iron and half silver alloy!
