Can someone explain why the answer is true. Will Mark brainliest.

Of 800 cars that drove on a street during a week, 0.75% exceeded the 25 miles per hour speed limit by more than 10 miles per hou

Murljashka [212]

.0075 * 800 = 6 cars

5 0

3 years ago

Read 2 more answers

I need to solve the equation please help me

lesantik [10]

Answer:

$\displaystyle x=\Big\{\frac{7\pi}{6}+2n\pi, \frac{3\pi}{2}+2n\pi, \frac{11\pi}{6}+2n\pi}\Big\}, n\in\mathbb{Z}$

Step-by-step explanation:

We are given the equation:

$4\sin^2(x)+6\sin(x)+2=0$

First, we can divide everything by 2:

$2\sin^2(x)+3\sin(x)+1=0$

Notice that we have an equation in quadratic form. Namely, if we make a substitution where u = sin(x), we acquire:

$2u^2+3u+1=0$

Solve for u. Factor:

$(2u+1)(u+1)=0$

Zero Product Property:

$2u+1=0\text{ or } u+1=0$

Solving for both cases:

$\displaystyle u=-\frac{1}{2}\text{ or } u=-1$

And by substitution:

$\displaystyle \sin(x)=-\frac{1}{2}\text{ or } \sin(x)=-1$

For the first case, recall that sin(x) is -1/2 for every 7π/6 and every 11π/6. Hence, for the first case, our solutions are:

$\displaystyle x=\frac{7\pi}{6}+2n\pi \text{ and } x=\frac{11\pi}{6}+2n\pi, n\in\mathbb{Z}$

Where n is an integer.

For the second case, sin(x) is -1 for every 3π/2. Thus:

$\displaystyle x=\frac{3\pi}{2}+2n\pi$

All together, our solutions are:

$\displaystyle x=\Big\{\frac{7\pi}{6}+2n\pi, \frac{3\pi}{2}+2n\pi, \frac{11\pi}{6}+2n\pi}\Big\}, n\in\mathbb{Z}$

4 0

3 years ago

Danielle and Emilia brought apples, bananas, and oranges to a fruit sale.

lilavasa [31]

Answer:

26 apples

Step-by-step explanation:

bananas, b= $0.50

oranges, o= $0.75

apples, a = $0.75

Total fruit sold = 50

Total Earned = $33.50

b + o + a = 50 Because the total number of all 3 fruits sold is 50

.5b + .75o + .75a = $33.50 The number of each fruit, multiplied by the price of each fruit, and added together is $33.50

They sold twice as many bananas than oranges.

If o is oranges, then 2o = b because there are twice as many bananas so:

b + o + a = 50

2o + o + a = 50

3o + a = 50

Now we can solve.

3o + a = 50

a = 50 - 3o

.5b + .75o + .75a = $33.50

.5(2o) + .75o + .75a = $33.50

o + .75o + .75a = $33.50

1.75o + .75a = $33.50

Two equations and 2 unknowns.

a = 50 - 3o

1.75o + .75a = $33.50 Plug in a to solve for o.

1.75o + .75(50 - 3o) = $33.50

1.75o + .75*50 - .75*3o = $33.50

1.75o + 37.5 - 2.25o = $33.50 Combine like terms

1.75o - 2.25o +37.5 = $33.50

-.5o + 37.5 = 33.5 Add .5o to each side so it cancels on the left.

37.5 = 33.5 + .5o Subtract 33.5 from each side

37.5 -33.5 = .5o

4 = .5o Divide each side by .5

4/.5 = o

8 = o

Now plug into a = 50 - 3o

a = 50 - 3(8)

a = 50 - 24

a = 26

So even though we know they sold 26 apples, let's finish solving to check our work.

b + o + a = 50

b + 8 + 26 = 50

b + 34 = 50

b = 50 - 34

b = 16

b = 2o

b = 2 (8)

b = 16 Which works! Now the last step of checking our work:

.5b + .75o + .75a = $33.50

.5(16) + .75(8) + .75(26) = $33.50

8 + 6 + 19.5 = $33.50

14 + 19.5 = $33.50

33.5 = $33.50 Yes! It works too!

bananas = 16

oranges = 8

apples = 26

3 0

3 years ago

A two-digit locker combination has two nonzero digits and no digit is repeated in any combination.

zzz [600]

Answer:

Answer choice C

Step-by-step explanation:

Similarly to the previous problem, there are two possibilities. In the first possibility, the chance of picking a digit lower than 7 is 6/9 or 2/3, because there are 6 digits below 7 and 9 digits in total. In this scenario, the probability of the second digit being below 7 is 5/8, since one of the digits has already been taken. The probability here is 5/8*6/9=5/12. In the other scenario, the probability of picking a number higher than 7 is 3/9 or 1/3. In this scenario, the probability of picking below 7 for the second digit is 6/8 or 3/4, because one of the digits has not been taken. 3/9*6/8= 1/4. Adding these two together, you get 8/12=2/3, or answer choice C. Hope this helps!

7 0

3 years ago

I need the answer and the work (it’s geometry)

Kisachek [45]

Answer:

D

Step-by-step explanation:

The starting point is B and the ray extends towards A.

So the asnwer is D.

6 0

3 years ago