15c + 70b < 4000 lbs
THE SIGN SHOULD HAVE A LINE UNDER IT FOR EQUAL TO! :)
hope this helps!
C) (0.85 + x/100)(250+145) does not give the correct answer.
Explanation
A) works; adding the two costs together is 250+145=395. We multiply this by 0.85 because 100%-15%=85%=0.85. We also have x% tax, which is represented by x/100, added to 100% of the value, or 1.00. Altogether this gives us
395(0.85)(1+x/100) = 395(0.85 + (0.85x/100)) = 395(0.85) + 395(0.85x/100)
= 395(0.85) + 395(0.0085x)
B) works; we have 250+145 for the original price; we have 85% = 0.85 of the value; we also have 100% + x%, which is (100+x)/100.
C) does not work; (0.85+x/100)(395) does not take into consideration that you are finding the tax after taking the 85%. This will simplify out to
0.85*395 + (x/100)(395) = 335.75 + 395x/100 = 335.75 + 3.95x, which is too much.
D) works; simplifying the expression from A, we have 395(0.85) + 395(0.0085x) = 335.75 + 3.3575x.
Answer: 2.815 kilograms
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Work Shown:
1 layer = 0.5 kg
5 layers = 5*(0.5 kg) = 2.5 kg
icing = 15 g = 15/1000 = 0.015 kg
1 candle = 100 g = 100/1000 = 0.1 kg
3 candles = 3*(0.1 kg) = 0.3 kg
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The five layers combine to 2.5 kg. On top of that we have 0.015 kg of icing, and then finally the three candles add 0.3 kg more weight.
The total weight is therefore: 2.5+0.015+0.3 = 2.815 kilograms
