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3 years ago

Solve by substitution 4x+2y=10 x-y=13

Mathematics

2 answers:

Savatey [412]3 years ago

8 0

4x+2y=10
x-y=13

x=13+y
4(13+y)+2y=10
52+4y+2y=10
52+6y=10
6y=-42
y=-7
x=13+y=13-7=6

frozen [14]3 years ago

6 0

Equation 1: 4x+2y=10
Equation 2: X-y= 13

From Equation 2:

X = 13+Y

Substitute X into Equation 1:

4(13+Y)+2Y=10
52+4Y+2Y=10
52+6Y=10
6Y=10-52
6Y=-42
Y=-7

Substitute Y into Equation 2:

X-(-7)= 13
X+7=13
X=6

Therefore: Y= -7; X=6

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FrozenT [24]

Answer:

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Step-by-step explanation:

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3 years ago

Solve 2 log x = log 36

zheka24 [161]

2log x= log 36
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8 0

3 years ago

Read 2 more answers

James is kayaking. He can row 3 mph in still water. If he can travel 6 miles downstream in the same amount of time that he can t

nekit [7.7K]

Answer: the speed of the current is 0.6 mph

Step-by-step explanation:

Let x represent the speed of the current.

James is kayaking. He can row 3 mph in still water. If he can travel 6 miles downstream. Assuming he went with the current, it means that his total speed while travelling downstream is (3 + x)

Time = distance/speed

Time taken to travel downstream is

6/(3 + x)

In the same amount of time, he can travel 4 miles upstream. Assuming he went against the current, it means that his total speed while travelling downstream is (3 - x). Time taken to travel upstream is

4/(3 - x)

Since the time is the same, then

6/(3 + x) = 4/(3 - x)

Cross multiplying, it becomes

6(3 - x) = 4(3 + x)

18 - 6x = 12 + 4x

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4 0

3 years ago

Use the net to compute the surface area of the three-dimensional figure.

Grace [21]

9514 1404 393

Answer:

382 square units

Step-by-step explanation:

The central four rectangles down the middle of the net are 9 units wide, and alternate between 8 and 7 units high. Then the area of those four rectangles is ...

9(8+7+8+7) = 270 . . . square units

The rectangles making up the two left and right "wings" of the net are 8 units high and 7 units wide, so have a total area of ...

2×(8)(7) = 112 . . . square units

Then the area of the figure computed from the net is ...

270 +112 = 382 . . . square units

Additional comment

You can reject the first two answer choices immediately, because they are odd. Each face will have an area that is the product of integers, so will be an integer. There are two faces of each size, so the total area of this figure must be an even number.

You may recognize that the dimensions are 8, 8+1, 8-1. Then the area is roughly that of a cube with dimensions of 8: 6×8² = 384. If you use these values (8, 8+1, 8-1) in the area formula, you find the area is actually 384-2 = 382. That area formula is A = 2(LW +H(L+W)).

3 0

3 years ago

If the mass of a material is 49 grams and the volume of the material is 7 cm^3, what would the density of the material be?

inysia [295]

The equation for density is:
$density = \frac{mass}{volume}$

To help you remember - my teacher told us to remember "We ♡ density," and the heart stands for $\frac{m}{v}$ , or $\frac{mass}{volume}$ . Cheesy, but it works!

Back to the problem:
We know the mass if 49g and the volume is 7 $cm^{3}$ , so plug these values into the equation for density:
$density = \frac{mass}{volume}\\
density = \frac{49\:g}{7\:cm^{3}} \\
density = 7\:g/cm^{3}$

Answer: The density is 7 g/ $cm^{3}$

4 0

4 years ago