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3 years ago

Can you please tell me where I did a mistake.

Mathematics

1 answer:

oksano4ka [1.4K]3 years ago

7 0

Last one should be less than 3/4

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Quiz! <br>2x + 2 = 4 <br>find x! <br>

lilavasa [31]

<h3>Solution</h3>

2x + 2 = 4
2x = 4 - 2
2x = 2
x = 2 ÷ 2
x = 1

<h3>Proof</h3>

2(1) + 2
= 2 + 2
= 4

7 0

3 years ago

Read 2 more answers

6895 round to nearest thousand

garik1379 [7]

Answer:

7000

Step-by-step explanation:

8 0

3 years ago

14 lessons costs $210. What would 72 lessons cost

Oksi-84 [34.3K]

Answer:

$1,080

Step-by-step explanation:

To solve, we can make a proportion

14 lessons are $210 and 72 lessons are $x

14/210=72/x

Cross multiply

14*x=210*72

14x=15120

To solve for x, we need to get x by itself. Since x is being multiplied by 14, divide both sides by 14.

14x/14=15120/14

x=1080

So, 72 lessons will cost $1,080

4 0

3 years ago

Read 2 more answers

If A and B are independent events with P(A) = .5 and P(B) = .2, find the following:a) P(A U B)b) P(A^c ? B^c)c) P(A^c U B^c)**No

Effectus [21]

If A and B are independent, then $P(A\cap B)=P(A)P(B)$ .

$P(A\cup B)=P(A)+P(B)-P(A\cap B)=P(A)+P(B)-P(A)P(B)$

$P(A\cup B)=0.5+0.2-0.5\cdot0.2$

$\boxed{P(A\cup B)=0.6}$

b. I'm guessing the ? is supposed to stand for intersection. We can use DeMorgan's law for complements here:

$P(A^c\cap B^c)=P(A\cup B)^c=1-P(A\cup B)$

$P(A^c\cap B^c)=1-0.6$

$\boxed{P(A^c\cap B^c)=0.4}$

c. DeMorgan's law can be used here too:

$P(A^c\cup B^c)=P(A\cap B)^c=1-P(A\cap B)=1-P(A)P(B)$

$P(A^c\cup B^c)=1-0.5\cdot0.2$

$\boxed{P(A^c\cup B^c)=0.9}$

4 0

3 years ago

La funcion que representa el beneficio obtenido por una empresa si vende x unidades de uno de sus productos es f(x)= -70x^2+2800

DerKrebs [107]

Answer:

$20$

Step-by-step explanation:

La función es

$f(x)=-70x^2+2800x-45000$

Diferenciando con respecto a $x$ obtenemos

$f'(x)=-140x+2800$

Igualar con cero

$0=-140x+2800\\\Rightarrow x=\dfrac{2800}{140}\\\Rightarrow x=20$

Doble derivada de la función

$f''(x)=-140$

Entonces, la función es máxima cuando el número de unidades vendidas, $x=20$ ,

3 0

3 years ago