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3 years ago

Which expression is equivalent to 83 ⋅ 8–7?

Mathematics

1 answer:

anastassius [24]3 years ago

3 0

I believe the answer to your question is 657

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How to turn 12/25 in precent

Len [333]

Answer:

48%

Step-by-step explanation:

To convert any fraction to a percentage, we need to multiply it by 100.

$\frac{12}{25}*100$

$= \frac{}{} 12*4$

= 48%

7 0

3 years ago

The area of rectangle A is double the area of rectangle B explain your answer

dybincka [34]

A's area is 4x3=12, B=2x3=6, so yes, A is twice the area of B

a Answer: YES

b Answer: One side doubled, the other stayed the same, so area doubled.

4 0

3 years ago

Solve y'' + 10y' + 25y = 0, y(0) = -2, y'(0) = 11 y(t) = Preview

svetlana [45]

Answer: The required solution is

$y=(-2+t)e^{-5t}.$

Step-by-step explanation: We are given to solve the following differential equation :

$y^{\prime\prime}+10y^\prime+25y=0,~~~~~~~y(0)=-2,~~y^\prime(0)=11~~~~~~~~~~~~~~~~~~~~~~~~(i)$

Let us consider that

$y=e^{mt}$ be an auxiliary solution of equation (i).

Then, we have

$y^prime=me^{mt},~~~~~y^{\prime\prime}=m^2e^{mt}.$

Substituting these values in equation (i), we get

$m^2e^{mt}+10me^{mt}+25e^{mt}=0\\\\\Rightarrow (m^2+10y+25)e^{mt}=0\\\\\Rightarrow m^2+10m+25=0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~[\textup{since }e^{mt}\neq0]\\\\\Rightarrow m^2+2\times m\times5+5^2=0\\\\\Rightarrow (m+5)^2=0\\\\\Rightarrow m=-5,-5.$

So, the general solution of the given equation is

$y(t)=(A+Bt)e^{-5t}.$

Differentiating with respect to t, we get

$y^\prime(t)=-5e^{-5t}(A+Bt)+Be^{-5t}.$

According to the given conditions, we have

$y(0)=-2\\\\\Rightarrow A=-2$

and

$y^\prime(0)=11\\\\\Rightarrow -5(A+B\times0)+B=11\\\\\Rightarrow -5A+B=11\\\\\Rightarrow (-5)\times(-2)+B=11\\\\\Rightarrow 10+B=11\\\\\Rightarrow B=11-10\\\\\Rightarrow B=1.$

Thus, the required solution is

$y(t)=(-2+1\times t)e^{-5t}\\\\\Rightarrow y(t)=(-2+t)e^{-5t}.$

6 0

3 years ago

During a school race, Sonic ran around the entire track 5 times in 10 seconds. Everyone was shocked by his speed, which was equa

Aleonysh [2.5K]

Step-by-step explanation:

there is no diagram here.

I assume that the race track is a rectangle in the middle and two half-circles at the left and right ends, and that the length of the rectangle is D = 2R. which makes the rectangle actually a square, as the width is the diameter of the (half-)circles, which is also 2R.

Sonic ran the track 5 times in 10 seconds with a speed of 321 m/s.

that means he ran 10×321 m in 10 seconds = 3210 m.

so, 5 times the track is 3210 m, which means that the track itself is 3210/5 = 642 m long.

and based on the assumptions above the track consists of 2 times the length of the rectangle (or square), and the full circumference of a circle with radius R (2 half-circles make one full circle).

we know the formula for the circumference of a circle :

2×pi×radius

so, we have then

642 = 2×2R + 2×pi×R = R×(4 + 2×pi)

R = 642 / (4 + 2×pi) = 62.43201701...

and when using the requested "cut-off" pi = 3.14, we get

R = 642 / (4 + 2×3.14) = 62.45136187...

and that is rounded 62.5

so, the second answer option is correct.

7 0

2 years ago

Read 2 more answers

What is the value of x?

kipiarov [429]

First of all, let’s find CB.
sin(45°) = CB : 6sqrt(2)
CB = 6
Now we can find CD
cos(60°) = x : 6
x = 3

7 0

2 years ago