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3 years ago

Describe and correct any error a student may have made when solving the equation

Mathematics

1 answer:

Lady_Fox [76]3 years ago

6 0

Answer:

The student made an error during the distributive property in the second step where they multiplied 0.15 by -0.2 to equal -0.3 when it should have been -0.03.

Step-by-step explanation:

$0.15(y-0.2)=2-0.5(1-y)\\0.15y-0.03=2-0.5+0.5y\\0.15y-0.03=1.5+0.5y\\100(0.15y-0.03)=100(1.5+0.5y)\\15y-3=150+50y\\15y-3-15y-150=150+50y-15y-150\\-153=35y\\-\frac{153}{35}=y$

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Arif's backyard is 22 by 36 meters. He wants to put a flower garden in the middle of the backyard, leaving a strip of grass of u

KIM [24]

Answer:

Paso 1:

Encuentra el área del patio trasero

Dado eso, el patio trasero mide 24 por 30 metros.

Área = largo x ancho

Área = 24 x 30 = 720

Por lo tanto, el área del patio trasero es de 720 metros cuadrados.

Paso 2:

Dado que el área de césped = 368 metros cuadrados

Luego, área de jardín = área de patio trasero - área de césped

área del jardín = 720 - 368

área de jardín = 352 metros cuadrados

Paso 3:

Encuentra las dimensiones del jardín

Sea "x" el ancho de la franja de césped

Entonces, las dimensiones del jardín son:

Longitud del jardín = 24 - 2x

Ancho del jardín = 30 - 2x

Luego,

área del jardín = (24 - 2x) (30 - 2x)

Factoriza el lado izquierdo

(x - 23) (x - 4) = 0

Por propiedad de factor cero,

x = 23 o x = 4

La solución x = 23 hace que las dimensiones del jardín sean negativas, por lo que la rechazamos

5 0

3 years ago

7.109) The leading brand of dishwasher detergent has a 30% market share. A sample of 25 dishwasher detergent customers was taken

Rina8888 [55]

Answer:

0.9021 = 90.21% probability that 10 or fewer customers choose the leading brand

Step-by-step explanation:

For each customer, there are only two possible outcomes. Either they choose the leading brand, or they do not. The probability of a customer choosing the leading brand is independent of any other customer, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

The leading brand of dishwasher detergent has a 30% market share.

This means that $p = 0.3$

A sample of 25 dishwasher detergent customers was taken.

This means that $n = 25$

a. What is the probability that 10 or fewer customers choose the leading brand?

This is:

$P(X \leq 10) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10)$

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{25,0}.(0.3)^{0}.(0.7)^{25} = 0.0001$

$P(X = 1) = C_{25,1}.(0.3)^{1}.(0.7)^{24} = 0.0014$

$P(X = 2) = C_{25,2}.(0.3)^{2}.(0.7)^{23} = 0.0074$

$P(X = 3) = C_{25,3}.(0.3)^{3}.(0.7)^{22} = 0.0243$

$P(X = 4) = C_{25,4}.(0.3)^{4}.(0.7)^{21} = 0.0572$

$P(X = 5) = C_{25,5}.(0.3)^{5}.(0.7)^{20} = 0.1030$

$P(X = 6) = C_{25,6}.(0.3)^{6}.(0.7)^{19} = 0.1472$

$P(X = 7) = C_{25,7}.(0.3)^{7}.(0.7)^{18} = 0.1712$

$P(X = 8) = C_{25,8}.(0.3)^{8}.(0.7)^{17} = 0.1651$

$P(X = 9) = C_{25,9}.(0.3)^{9}.(0.7)^{16} = 0.1336$

$P(X = 10) = C_{25,10}.(0.3)^{10}.(0.7)^{15} = 0.0916$

Then

$P(X \leq 10) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10) = 0.0001 + 0.0014 + 0.0074 + 0.0243 + 0.0572 + 0.1030 + 0.1472 + 0.1712 + 0.1651 + 0.1336 + 0.0916 = 0.9021$

0.9021 = 90.21% probability that 10 or fewer customers choose the leading brand

3 0

3 years ago

???????????????????????????????????????????

shusha [124]

For question 1, just plug in -2 as h.

 $-2(-2)^2-(-2)+2$

You would get...

$h(-2)=-4$

Hope this helped! -4, or option 1, is correct!

4 0

3 years ago

How many vertices does a cube have

PolarNik [594]

A cube has 8
A square has 4

4 0

3 years ago

Read 2 more answers

the sum of the two trains is 723.5 mph if the speed of the first train is 12.5 mph faster than that of the second train find the

jonny [76]

First, let's see if we can rewrite this word problem a little bit more mathematically. We won't get to mathy or technical so no worries. We just want to look at it in a more straightforward way, if we can.

Train A's mph plus Train B's mph summed equal 723.5 mph. Train A's mph is greater than Train B's mph by 12.5 mph.
So what should we do to solve this problem? Since we are dealing with two of something and we know the value of the two combined, it might make sense to start by dividing that value by 2.
723.5 / 2 = 361.75. If the two trains were travelling at the same speed, we would be done. Unfortunately, they are not so we need to think about this some more.
Train A is going 12.5 mph faster than Train B. Let's rewrite.
Train A mph = 12.5 + 361.75 = 374.25 Okay, so Train A is travelling at a speed of 374.25 mph. So we're done right? Not exactly. We are asked to fing the speeds of BOTH trains. How do we find the speed of Train B? We have added a portion of the combined total to Train A. It seems to follow, then, we should probably subtract the same portion from Train A. What are we going to do? You guessed it! Rewrite.
Train B mph = 361.75 - 12.5 = 349.25 HA HA! We seem to have figured it out. Let's do one last thing to check our work. Let's add the two trains' speeds together. If we did this right, we should get our summed value of 723.5 mph
374.25 + 349.25 = 723.5
Pat yourself on the back! We did it!

374.25 + 349.25 =

3 0

3 years ago

Read 2 more answers