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Tamiku [17]
3 years ago
14

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

Mathematics
1 answer:
Step2247 [10]3 years ago
7 0

Answer:

Answer:

Answer is: 32 nickels and 23 dimes.

x - number of nickels .

y -number of dimes.

two equations in two unknowns:

1) x + y = 55

2) 0,05x + 0,1y = 3,90.

nickel is a five-cent coin.

dime is a ten-cent coin.

solve equation 1) for x and substitute for x in equation 2)

x = 55 - y

0,05·(55 - y) + 0,1y = 3,902,75 - 0,05y + 0,1y = 3,90

0,05y = 1,15

y = 23.

x = 55 - 23 = 32.

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The equation of line WX is 2x + y = -5. What is the equation of a line perpendicular to line WX in slope-intercept form that con
sveticcg [70]

Answer:

The third choice is the one you want

Step-by-step explanation:

If we are to write the equation of a line perpendicular to WX, we first must determine what the slope of the WX is, because the line perpendicular to WX has a slope that is the flip of the slope of WX with the opposite sign.  Solving for y takes care of finding the slope of WX:

2x + y = -5 so

y = -2x - 5

The slope is -2.  That means that the reciprocal slope is 1/2.  Using that slope along with the coordinates x = -1 and y = -2, we first write the line using point-slope form and then solve it for y.  Start by filling in the m, the x value and the y value:

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Getting rid of the double negatives gives us:

y+2=\frac{1}{2}(x+1)

Distributing then gives us:

y+2=\frac{1}{2}x+\frac{1}{2}

And finally solving for y (I am going to express the 2 on the left as 4/2 when I move it by subtraction in order to add those fractions):

y=\frac{1}{2}x+\frac{1}{2}-\frac{4}{2}

And the final equation in slope-intercept form is:

y=\frac{1}{2}x-\frac{3}{2}

8 0
2 years ago
PLEASE HELP ASAP
zheka24 [161]

Answer:

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Step-by-step explanation: have a good day!

5 0
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Rewrite with positive exponents: 7^-3
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Answer:

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Step-by-step explanation:

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3 years ago
The scores on a standardized test are normally distributed with the mean of 750 and standard deviation 70. Find the probability
mafiozo [28]
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3 years ago
Read 2 more answers
HELP I attracted a picture????
posledela

Answer:

D. 187 m²

Step-by-step explanation:

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34 x 11 ÷ 2 = 187

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hope this helps:)

6 0
2 years ago
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