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3 years ago

Last one, Help with math please 18-20 on the pdf. I do not know how to post a picture I am so sorry.

Mathematics

2 answers:

tatuchka [14]3 years ago

8 0

Question 18
The answer is 4 days.
Because,
Kevin =3×n
Anita =4+ (2×n)
Equating the two equations.
3n=4+2n
3n-2n=4
n=4

Question 19
When the solution is (4,1), it means the value of y=1 and x=4.
The answer is;
y=x-3
y=-3x+13. Since when the values of x and y are substituted they satisfy the system.

Question 20
The system has no solution.
This is because the line are parallel and they do not intersect to give a solution.

soldier1979 [14.2K]3 years ago

6 0

Hello,
Please, see the attached files.
Thanks.

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Segment AB has endpoints with coordinates A: (-4, -7) and B: (8, -4). Determine the value of the x-coordinate of the interior po

Nadusha1986 [10]

Answer:

≈ 3.4 

Step-by-step explanation:

Coordinates of the point that divide segment with endpoints A( $x_{1}$ , $y_{1}$ ) and B( $x_{2}$ , $y_{2}$ ) in a ratio a : b are

$\frac{bx_{1} +ax_{2} }{a+b}$ , $\frac{by_{1} +ay_{2} }{a+b}$ )

A(- 4, - 7)

B(8, - 4)

Ratio 8 : 5

x-coordinate is $\frac{5(-4)+8(8)}{8+5}$ = $\frac{44}{13}$ ≈ 3.4

3 0

3 years ago

When a spherical balloon is filled with air, it has a radius of 3 inches. Which of these gives the best estimate for the volume

marysya [2.9K]

By definition, the volume of a sphere is given by:
V = (4/3) * (pi) * (r ^ 3)
where,
r: radius of the sphere.
Substituting we have:
V = (4/3) * (pi) * ((3) ^ 3) = 113.08 in ^ 3
answer
the best estimate for the volume of air in the balloon in cubic inches is
C. 113.1

3 0

3 years ago

Read 2 more answers

A train leaves San Diego at 1:00 pm. A second train leaves the same city in the same direction at 3:00 pm. The second train trav

Soloha48 [4]

Answer:

The speed of the first train is 45 mph and the speed of the second train is 75 mph

Step-by-step explanation:

Let x represent the speed of the first train in mph. Since the second train, is 30 mph faster then the first, therefore the speed of the second train is (x + 30).

The first train leaves at 1:00 pm, therefore at 6:00 pm, the time taken is 5 hours. Therefore the distance covered by the first train at 6:00 pm = x mph * 5 hours = 5x miles

The second train leaves at 3:00 pm, therefore at 6:00 pm, the time taken is 3 hours. Therefore the distance covered by the second train at 6:00 pm = (x + 30) mph * 3 hours = (3x + 90) miles

Since the second train overtakes the first at 6:00 pm, hence:

3x + 90 = 5x

2x = 90

x = 45

Therefore the speed of the first train is 45 mph and the speed of the second train is 75 mph (45 mph + 30 mph).

7 0

3 years ago

(0.4y - 3)/(1.5y + 9) = -7/5

Jlenok [28]

Answer:

y = -3.84.

Step-by-step explanation:

(0.4y - 3)/(1.5y + 9) = -7/5

Cross multiply:

2y - 15 = -10.5y - 63

12.5y = -48

y = -3.84

6 0

3 years ago

BRAINLIEST+ STARS!!

nasty-shy [4]

To find the density:

⇒ must find the relationship between the density, mass, and volume

⇒ $Density = \frac{mass}{volume}$

Let's examine the information given:

weight: 1890g
dimensions: 8cm * 5cm* 5cm

Let's first find the volume:

⇒ the volume is the dimensions multiplied together

$Volume = 8cm * 5cm * 5cm = 200cm^3$

LEt's calculate the density now:

$Density = \frac{1890g}{200cm^3} =9.45g/cm^3$

Answer: The density of the copper is 9.45g/cm^3 or Choice (A)

Hope that helps!

6 0

2 years ago