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3 years ago

A pile of 55 coins, consisting of nickels and dimes, is worth $3.90. find the number of each.

2 answers:

8 0

<span>N + D = 55 coins (1) (N stands for nickels, 5N + 10D = 390 cents (2) D stands for dimes) Simplify (2) by canceling the factor 5 in both sides: N + 2D = 78 (3) Subtract eq(1) from eq(3). You will get D = 78 - 55 = 23. Answer. 23 dimes and 55-23 = 32 nickels. Check. 23*10 + 32*5 = 390 cents</span>

kari74 [83]3 years ago

7 0

N + D = 55 coins (1) (N stands for nickels, 5N + 10D = 390 cents (2) D stands for dimes) Simplify (2) by canceling the factor 5 in both sides: N + 2D = 78 (3) Subtract eq(1) from eq(3). You will get D = 78 - 55 = 23. Answer. 23 dimes and 55-23 = 32 nickels. Check. 23*10 + 32*5 = 390 cent

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An arc subtends a central and measuring pi/2 radians.

Sindrei [870]

Answer:

1/4th

Step-by-step explanation:

This comes from knowing the unit circle in both radians and degrees. However, you could also calculate it from knowing that 360 degrees is 2 $\pi$ radians. What you'll find is that $\frac{\pi }{2}$ radians is 90 degrees, or 1/4th of the circle. This means that an arc measuring $\frac{\pi }{2}$ radians will be 1/4th of the entire circumference.

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3 years ago

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hichkok12 [17]

Answer:

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Step-by-step explanation:

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3 years ago

X² - 40x-129 resolve into factor

Lelu [443]

Answer:

(x - 43)(x + 3)

Step-by-step explanation:

consider the factors of the constant term (- 129) which sum to give the coefficient of the x- term (- 40)

the factors are - 43 and + 3 , since

- 43 × + 3 = - 129 and - 43 + 3 = - 40 , then

x² - 40x - 129 = (x - 43)(x + 3) ← in factored form

8 0

2 years ago

Add these fractions, giving your answer in simplest form. <br> 2 1/4 + 3 1/5

dalvyx [7]

5 2/8 beacuse if you add it up that what it makes

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3 years ago

Read 2 more answers

A chain of retail computer stores opened 2 stores in its first year of operation. After 8 years of operation, the chain consiste

Helen [10]

Answer:

0.66

Step-by-step explanation:

The exponential growth equation is expressed as;

S(t) = S0e^kt

S(t) is the number of stores after t years

S0 is the initial number of stores

If a chain of retail computer stores opened 2 stores in its first year of operation then at t = 1, S(t) = 2. Substitute into the equation;

2 = S0e^k(1)

2 = S0e^k .... 1

Also if after 8 years of operation, the chain consisted of 206 stores, this means at t = 8, S(t) = 206. Substitute into the equation;

206 = S0e^k(1)

206 = S0e^8k .... 2

Next is to calculate the value of k

Divide equation 2 by 1;

$\frac{206}{2} = \frac{S0e^{8k} }{S0e^k }\\103 = e^{7k}\\apply \ ln \ to \ both \ sides\\ln103 = lne^{7k}\\ln103 = 7k\\k = \frac{ln103}{7}\\k = \frac{4.6347}{7} \\k = 0.6621$

Hence the value of k to the nearest hundredth is 0.66

4 0

3 years ago