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3 years ago

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Kat has 19 coins, all quarters and dimes, that are worth a total of $4. The system of equations that can be used to the number o

f quarters,q, and the number of dimes,d, she has shown

1 answer:

Luden [163]3 years ago

7 0

<span>q + d=19 0.25q + 0.1d=4
</span><span> (d) -0.1(q + d=19) 0.25q + 0.1d=4 Opposites cancel -0.1q -0.1 d=1.9 0.25q + 0.1d=4</span>

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grigory [225]

Answer:

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Step-by-step explanation:

You can find the slope by taking two points on the graph, and making the one that occurs earlier in the graph (from left to right) the first point (x1, y1) and the one that occurs later in the graph the second point (x2, y2). The equation is m (or slope)=(y2-y1)/(x2-x1). I took the first two points in the table for this. m=(12-18)/-4-(-8)

the double negative on the bottom becomes an addition=> (12-18)/(-4+8)

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this fraction can be reduced to -3/2, which is the slope of the graph.

Now, use point slope form (y-y1=m(x-x1)) to find the equation of the graph. Plug any coordinate on the graph in for x1 and y1 here. It should be correct as long as it is a point on the graph, but I am using the point (-8, 18) here.

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3 years ago

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3 years ago

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Marysya12 [62]

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Step-by-step explanation:

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3 years ago

) The density of oil in a circular oil slick on the surface of the ocean at a distance of r meters from the center of the slick

Feliz [49]

Answer:

Therefore the mass of the of the oil is 409.59 kg.

Step-by-step explanation:

Let us consider a circular disk. The inner radius of the disk be r and the outer diameter of the disk be (r+Δr).

The area of the disk

=The area of the outer circle - The area of the inner circle

= $\pi (r+\triangle r)^2- \pi r^2$

$=\pi [r^2+2r\triangle r+(\triangle r)^2-r^2]$

$=\pi [2r\triangle r+(\triangle r)^2]$

Since (Δr)² is very small, So it is ignorable.

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We know,

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Therefore

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= 409.59 kg (approx)

Therefore the mass of the of the oil is 409.59 kg.

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