The question is asking for mass/unit of volume.
Therefore the density of the material would be 6400kg/0.8m^3. You then want to change the bottom into a 1 by multiplying the top and bottom both by 10/8. You now have 8000kg/m^3, which is the solution.
8x +7y = 39 multiply everything by 2
2(8x +7y = 39)
16x +14y = 78
+4x - 14y= -68
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20x = 10
20x /20 = 10/20
x = 1/2
Plug x into first formula
8 x + 7y =39
8(1/2) 7y=39
4+ 7y =39
4-4+7y =39-4
7y =35
7y/7 = 35/7
y = 5
(1/2, 5)
4n - t<span>he length of a rectangle
4n : 2 = 2n - </span>the width of a rectangle
P = (4n + 2n) * 2
P = 12n
12n : 2 = 6n - the perimeter of the equilateral triangle
P = 3a
6n = 3a
a = 6n : 3
a = 2n - <span>the side length of the triangle - answer.</span>
From the diagram, we are given that triangle ABC and triangle ADC shares the same side AC, so it means both triangles have one congruent side.
We are also given that angle BAC and angle DAC are equal.
If we want to prove the triangles congruent using Angle-Angle-Side congruent postulate, we need to see one angle in each triangle that is congruent. We will need the information either: ACB = ACD or ABC = ADC
Correct answer: fourth option
