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3 years ago

Mary roller skates with a constant speed of 8 km/h. How long will she take to travel a distance of 16 kilometres?

1 answer:

8 0

Mary has a speed of 8 kilometers per hour, you multiply 8 km/h by 2 to get 16 kilometers and 2 hours. It will take her 2 hours to travel 16 km

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Maria and Curtis both study a second language. Maria studies German 3 hours per week, and Curtis studies French 2 hours per week

AveGali [126]

Answer:2

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

Philip made a total of 9 bracelets and necklaces from 120 inches of cord. He used 8 inches of cord for each bracelet and 20 inch

Viktor [21]

Answer:

So Philip made 5 bracelets and 4 necklaces.

Step-by-step explanation:

Let x = number of bracelets and y = number of necklaces.

Since we have a total of 9 bracelets and necklaces,

x + y = 9 (1)

Also, we have 8 inches of cord for each bracelet and 20 inches of cord for each necklace, then the total length for the bracelet is 8x and that for the necklace is 20y.

So, the total length for both is 8x + 20y. Since the total length of cord used is 120 inches,

8x + 20y = 120 (2)

Simplifying it we have

2x + 5y = 30 (3).

Writing equations (1) and (3) in matrix form, we have

$\left[\begin{array}{ccc}1&1\\2&5\end{array}\right] \left[\begin{array}{ccc}x\\y\end{array}\right] = \left[\begin{array}{ccc}9\\30\end{array}\right]$

Using Cramer's rule to solve for x and y,

$x = det \left[\begin{array}{ccc}9&1\\30&5\end{array}\right] /det \left[\begin{array}{ccc}1&1\\2&5\end{array}\right] \\$

x = (9 × 5 - 30 × 1) ÷ (1 × 5 - 1 × 2)

x = (45 - 30) ÷ (5 - 2)

x = 15 ÷ 3

x = 5

$y = det \left[\begin{array}{ccc}1&9\\2&30\end{array}\right] /det \left[\begin{array}{ccc}1&1\\2&5\end{array}\right] \\$

y = (30 × 1 - 9 × 2) ÷ (1 × 5 - 1 × 2)

y = (30 - 18) ÷ (5 - 2)

y = 12 ÷ 3

y = 4

So Philip made 5 bracelets and 4 necklaces.

3 0

3 years ago

Give the equation of the circle centered at the origin and passing through the point (0,5)

Julli [10]

Answer:

$x^{2} +y^{2}=25$

Step-by-step explanation

The standard equation of a circle centered at origin is $x^{2} +y^{2} =r^{2}$

r = radius of the circle

The circle is passing through the point (0,5)

∴ radius $r=\sqrt{(0-0)^{2}+(5-0)^{2} }$

$r=\sqrt{0+25}$

$r=\sqrt{25}$

$r^{2}=25$

∴ The equation of the circle is

$x^{2} +y^{2} = 25$

5 0

2 years ago

2.199 rounded to the nearest whole number

steposvetlana [31]

Rounding 2.199. The tenths digit is 1, which is 4 or less, so you will round down. Re-write 2.199 without the decimal places: 2 . So 2.199 rounds to 2.

3 0

3 years ago

(9 – 23) + |47 – 16|

laiz [17]

You answer is: 17

Or otherwise B. is your correct answer.

(9 - 23) = -(14)

| 47 - 16| = 31

31 + (-14) = 17

5 0

3 years ago