Ask question

Ask question

All categories

2 years ago

9

Marika solved the equation (6x + 15)2 + 24 = 0. Her work is below. 1. (6x + 15)2 = –24 2. = 3. 6x + 15 = 4. 6x = – 15 5. x = Ana

lyze Marika’s steps. Which statement is true about her work? In step 2, Marika should have simplified to be . There are no real solutions to this equation because the square root of a negative number is not a real number. There should be two real solutions to this equation because = . Marika correctly solved this equation.

2 answers:

Licemer1 [7]2 years ago

8 0

The answer would be B, there are no real solutions to the secretion because the Square root of a negative number is not a real number.

Lina20 [59]2 years ago

6 0

Given equation: $(6x + 15)^2 + 24 = 0.$

First step Marika applied to get rid 24 from left side.

24 is added on left side of the equation.

The reverse operation of addition is subtract.

So, we need to subtract 24 from both sides in first step.

$(6x + 15)^2 + 24-24 = 0-24$

On simplifying it gives:

$(6x+15)^2= -24.$ .

Then she took square root to get rid square from left side .

But we can see that 24 is a negative number.

So, we can't take square root of 24.

Therefore, in second step the did some mistake:

<h3><em>There are no real solutions to this equation because the square root of a negative number is not a real number.</em></h3>

You might be interested in

3.82e+7 in standard form shown in calculator display

ser-zykov [4K]

E+7 means 10^+7
basically move the decimal place 7 placs to right so it would be aprox
38200000.0

3 0

2 years ago

Read 2 more answers

Accrotime is a manufacturer of quartz crystal watches. Accrotime researchers have shown that the watches have an average life of

Gelneren [198K]

Answer:

a

$P(X < 24 )= 21.186\%$

b

$x = 19.78 \ months$

Step-by-step explanation:

From the question we are told that

The mean is $\mu = 26 \ months$

The standard deviation is $\sigma = 4 \ months$

Generally 2 year is equal to 24 months

Generally the percentage of total production will the company expect to replace is mathematically represented as

$P(X < 24 )= P(\frac{X - \mu }{ \sigma} < \frac{24 - 26}{4} )$

Generally $\frac{X - \mu}{\sigma } =Z (The \ standardized \ value \ of \ X )$

$P(X < 24 )= P(Z < -0.8 )$

Generally from the z-table

$P(Z < -0.8) = 0.21186$

So

$P(X < 24 )= 0.21186$

Converting to percentage

$P(X < 24 )= 0.21186 * 100$

=> $P(X < 24 )= 21.186\%$

Generally the duration that should be the guarantee period if Accrotime does not want to make refunds on more than 6% is mathematically evaluated as

$P(X < x) = P(\frac{X - \mu }{\sigma} < \frac{x - 26}{4} )= 0.06$

=> $P(X < x) = P(Z < \frac{x - 26}{4} )= 0.06$

From the normal distribution table the z-score for 0.06 at the lower tail is

$z = -1.555$

So

$\frac{x - 26}{4} = -1.555$

=> $x = 19.78 \ months$

6 0

2 years ago

Mrs. Garcia borrowed some money at the rate of 4% per annum for the first year, at the rate of 6% pe r annum for the next 2 year

s2008m [1.1K]

Answer: ₱40,909.1

Step-by-step explanation:

Given data:

Rate for first year = 4%

Rate for next two years = 6%

Rate for the next 3 years = 7.5%

Interest paid back after 5years = ₱ 15,750

Solution:

How much did she borrow.

= let the sum borrowed be P

= P * 4 / 100

= 4P/100

= 1P/25.

For the next two years

= P* 6 * 2/100

= 12P/100

= 3P/25

For the next 3years

= P* 7.5*3/100

= 22.5P/100

= 9P/40.

1P/25 + 3P/25 + 9P/40 = 15750

77P/200 = 15750

P = 15750 * 200 / 77

P = 315,0000/77

P = ₱40,909.1

The amount borrowed is ₱40,909.1

5 0

2 years ago

Which system of equations can be used to find the roots of the equation 12 x 3-5x=2 x 2+x+6

kirill [66]

Answer:

Option (a) is correct.

The system of equation becomes

$y=12x^3-5x\\\\ y=2x^2+x+6$

Step-by-step explanation:

Given : Equation $12x^3-5x=2x^2+x+6$

We have to construct a system of equations that can be used to find the roots of the equation $12x^3-5x=2x^2+x+6$

Consider the given equation $12x^3-5x=2x^2+x+6$

To construct a system of equation put both sides of the given equation equal to a same variable.

Let the variable be "y", Then the equation $12x^3-5x=2x^2+x+6$

becomes,

$12x^3-5x=y=2x^2+x+6$

Thus, The system of equation becomes

$y=12x^3-5x\\\\ y=2x^2+x+6$

Option (a) is correct.

8 0

2 years ago

Read 2 more answers

Jack is 27 years older than Susan. In 5 years he will be 4 times as old as she is. Find the present ages of jack and Susan

riadik2000 [5.3K]

X - Jack's age
y - Susan's age

Jack is 27 years older than Susan.
$x=y+27$

In 5 years he will be 4 times as old as she is.
$x+5=4(y+5)$

The system of equations:
$x=y+27 \\ x+5=4(y+5) \\ \\ \hbox{substitute y+27 for x in the 2nd equation:} \\ y+27+5=4(y+5) \\ y+32=4y+20 \\ y-4y=20-32 \\ -3y=-12 \\ y=\frac{-12}{-3} \\ y=4 \\ \\ x=y+27=4+27=31$

Jack is 31 years old and Susan is 4 years old.

5 0

2 years ago