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2 years ago

Help im suck at math pleasee 1. simplify 2.9+0.3-12-6 2. simplify 2.9-5.3-4n+6

Mathematics

1 answer:

ziro4ka [17]2 years ago

8 0

Answer:

n=0.956

Step-by-step explanation:

2.9+6=8.9 and 5.3n - 4n = -9.3n so, 8.9 - 9.3n = ? so -9.3n = -8.9 and 0.3n = 8.9 so n = 8.9/9.3 which is 0.956

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Determine the volume in litres of 14kg of petrol of density 700kg/m³

valkas [14]

Answer:

$p = \frac{m}{v}$

Step-by-step explanation:

Density is the ratio of an object's mass to its volume, and it measures how compact an object is. The density of an object, p, is directly proportional to its mass, m, and inversely proportional to its volume, V:

$p = \frac{m}{v}$

4 0

2 years ago

A new car sells for $27,500. The value of the car decreases by 14% annually. You want to sell the car when it's worth about $400

NemiM [27]

Answer: 13 years.

Step-by-step explanation:

The price decreases by 14% anually

To find the decimal form, you have 14%/100% = 0.14

So, the year zero, the price is $27,500

After one year, the price is:

P = $27,500 - 0.14*$27500 = $27,500*(0.86)

After the second year, the price is:

P = $27,500*(0.86)^2

and so on, so we want to find x such that:

P = $27,500*(0.86)^x = $4000

0.86^x = $4000/$27,500

Now, using the natural logaritm rule:

a^x = b

x = ln(a)/ln(b)

x = ln($4000/$27,500)/ln(0.86) = 12.8

We can round it up to 13, so after 13 years the price of the car is about $4000

7 0

3 years ago

Carrie and brent leave home at the same time. carrie drives due east at a rate of 30 mph, while brent drives due south at a rate

Helga [31]

<h3>They are 268 miles far apart after 4 hours</h3>

<h3>Further explanation</h3>

Acceleration is rate of change of velocity.

$\large {\boxed {a = \frac{v - u}{t} } }$

$\large {\boxed {d = \frac{v + u}{2}~t } }$

<em>a = acceleration ( m/s² )</em>

<em>v = final velocity ( m/s )</em>

<em>u = initial velocity ( m/s )</em>

<em>t = time taken ( s )</em>

<em>d = distance ( m )</em>

Let us now tackle the problem !

<u>Given :</u>

v₁ = 30 mph due east

v₂ = 60 mph due south

t = 4 hours

<u>Unknown :</u>

displacement = d = ?

<u>Solution :</u>

$d_1 = v_1 \times t$

$d_1 = 30 ~ mph \times 4 ~ h$

$d_1 = \boxed {120 ~ miles}$

$d_2 = v_2 \times t$

$d_2 = 60 ~ mph \times 4 ~ h$

$d_2 = \boxed {240 ~ miles}$

$d^2 = (d_1)^2 + (d_2)^2$

$d^2 = 120^2 + 240^2$

$d^2 = 72000$

$d = \sqrt{72000}$

$d = 120\sqrt{5} ~ miles$

$d \approx \boxed {268 ~ miles}$

<h2>Conclusion :</h2><h3>They are 268 miles far apart after 4 hours</h3>

<h3>Learn more</h3>

Velocity of Runner : brainly.com/question/3813437
Kinetic Energy : brainly.com/question/692781
Acceleration : brainly.com/question/2283922
The Speed of Car : brainly.com/question/568302

<h3>Answer details</h3>

Grade: High School

Subject: Physics

Chapter: Kinematics

Keywords: Velocity , Driver , Car , Deceleration , Acceleration , Obstacle , Speed , Time , Rate

6 0

3 years ago

Read 2 more answers

PLEASEEE

zzz [600]

Answer:

13.4

Step-by-step explanation:

AB =2DC

So, DC=AB/2

Now, AB/AC=DE/DC

AB/28=13/(AB/2)

AB²=13×28×2

AB=√728

AB=26.98

now, DC=AB/2

=13.4

6 0

2 years ago

R leaks out of a barrel so that the rate of change in the water level is proportional to the square root of the depth of the wat

Irina-Kira [14]

Let y(t) represent the level of water in inches at time t in hours. Then we are given ...
y'(t) = k√(y(t)) . . . . for some proportionality constant k
y(0) = 30
y(1) = 29

We observe that a function of the form
y(t) = a(t - b)²
will have a derivative that is proportional to y:
y'(t) = 2a(t -b)

We can find the constants "a" and "b" from the given boundary conditions.
At t=0
30 = a(0 -b)²
a = 30/b²
At t=1
29 = a(1 - b)² . . . . . . . . . substitute for t
29 = 30(1 - b)²/b² . . . . . substitute for a
29/30 = (1/b -1)² . . . . . . divide by 30
1 -√(29/30) = 1/b . . . . . . square root, then add 1 (positive root yields extraneous solution)
b = 30 +√870 . . . . . . . . simplify

The value of b is the time it takes for the height of water in the tank to become 0. It is 30+√870 hours ≈ 59 hours 29 minutes 45 seconds

5 0

3 years ago