Answer:
x=1, y=1. (1, 1). The answer is D).
Step-by-step explanation:
3x-5y=-2
4x-7y=-3
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4(3x-5y)=4(-2)
-3(4x-7y)=-3(-3)
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12x-20y=-8
-12x+21y=9
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y=1
3x-5(1)=-2
3x-5=-2
3x=-2+5
3x=3
x=3/3
x=1
Ben's estimate gives 7 g of nickel; the actual amount is 8.03 g.
In 1 g of the substance, there is 0.52 g of copper and 0.25 g of zinc; this gives
0.52+0.25 = 0.77 g of the substance.
The remaining part of the substance is nickel:
1-0.77 = 0.23 g of nickel.
Using Ben's estimate, 0.2 g of nickel per gram of substance, we have
0.2(35) = 7 g of nickel in 35 g of the substance.
The actual amount is 0.23(35) = 8.03 g of nickel in 35 g of the substance.
86.436 divided by 12 equals 7.203. 34.86 divided by 4 equals 8.715. 5.87 divided by 15 equals 0.38.
Answer:
The school where the donut and coffee day will take place.
The number of boxes of donuts the PTO bought.
The number of cups of coffee the PTO bought.
