<span>A = P (1 + r/n)<span> (nt)
</span></span>A<span> = the future value of the investment</span>
P<span> = (the initial deposit or loan amount)</span>
r<span> = the annual interest rate (decimal)</span>
n<span> = the number of times that interest is compounded per year</span>
t<span> = the number of years the money is invested
</span>
Answer:
1/4
Step-by-step explanation:
15 out of the 20 books are horses. 5 of those are nature. 5/20 is the fraction, but can be simplified to 1/4
The right answer is Option A.
Step-by-step explanation:
Let,
x be the postcards
y be the large envelops
According to given statement;
14x+5y=12 Eqn 1
10x+15y=24.80 Eqn 2
Multiplying Eqn 1 by 3;
![3(14x+5y=12)\\42x+15y=36\ \ \ Eqn \ 3](https://tex.z-dn.net/?f=3%2814x%2B5y%3D12%29%5C%5C42x%2B15y%3D36%5C%20%5C%20%5C%20Eqn%20%5C%203)
Subtracting Eqn 2 from Eqn 3;
![(42x+15y)-(10x+15y)=36-24.80\\42x+15y-10x-15y=11.20\\32x=11.20\\](https://tex.z-dn.net/?f=%2842x%2B15y%29-%2810x%2B15y%29%3D36-24.80%5C%5C42x%2B15y-10x-15y%3D11.20%5C%5C32x%3D11.20%5C%5C)
Dividing both sides by 32
![\frac{32x}{32}=\frac{11.20}{32}\\x=0.35](https://tex.z-dn.net/?f=%5Cfrac%7B32x%7D%7B32%7D%3D%5Cfrac%7B11.20%7D%7B32%7D%5C%5Cx%3D0.35)
Putting x=0.35 in Eqn 1;
![14(0.35)+5y=12\\4.90+5y=12\\5y=12-4.90\\5y=7.10](https://tex.z-dn.net/?f=14%280.35%29%2B5y%3D12%5C%5C4.90%2B5y%3D12%5C%5C5y%3D12-4.90%5C%5C5y%3D7.10)
Dividing both sides by 5
![\frac{5y}{5}=\frac{7.10}{5}\\y=1.42](https://tex.z-dn.net/?f=%5Cfrac%7B5y%7D%7B5%7D%3D%5Cfrac%7B7.10%7D%7B5%7D%5C%5Cy%3D1.42)
Therefore, one large envelope costs $1.42
The right answer is Option A.
Keywords: linear equations, subtraction
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