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3 years ago

Solve 3c + 4 = -4c - 17 A. 3 B. -3 C. 21 D. -21

1 answer:

8 0

3c + 4 = -4c - 17

3c = -4c - 17 - 4 Subtracted 4 from both sides

3c + 4c = -21 Added 4c to both sides. (-17 - 4 = -21)

7c = -21 Combined like terms (4c + 3c = 7c)

c = -3 Divided 7 both sides

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Don wants to keep his favorite pine tree from being uprooted by heavy winds. He plans to tie 3 sections of rope to a band on the

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Answer:64 feet i think

Step-by-step explanation:

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2 years ago

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Which of the following would best be solved using factoring the difference of squares? 2² + 3x - 10 = 0 O 3r² + 12x = 8 2³ +52²

IgorC [24]

Given: Different equations

To Determine: Which would be best solved using difference of two squares

Solution

The factorization of a difference of two squares is given below

$a^2-b^2=(a-b)(a+b)$

Let us examine each of the given equation

$\begin{gathered} x^2+3x-10=0 \\ x^2-2x+5x-10=0 \\ x(x-2)+5(x-2)=0 \\ (x-2)(x+5)=0 \end{gathered}$ $\begin{gathered} 3x^2+12x=8 \\ 3x^2+12x-8=0 \end{gathered}$ $\begin{gathered} x^3+5x^2-9x-45=0 \\ x^2(x+5)-9(x+5)=0 \\ (x+5)(x^2-9)=0 \\ x^2-9=x^2-3^2=(x+3)(x-3) \\ Therefore \\ (x+5)(x+3)(x-3)=0 \end{gathered}$ $\begin{gathered} x^2-25=0 \\ x^2-5^2=0 \\ (x+5)(x-5)=0 \end{gathered}$

From the above,

$\begin{gathered} x^3+5x^2-9x-45=0 \\ AND \\ x^2-25=0 \end{gathered}$

The two equation above can be solved by difference of two square, but the equation below is the easiest solved using differnce of two square

x² - 25 = 0

3 0

1 year ago

How to show the tens fact you used. write the difference. <br> 14-6=____<br> 10-___=____

trasher [3.6K]

14 - 6 = 8
10 - 6 = 4

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3 years ago

A researcher examines 27 water samples for mercury concentration. The mean mercury concentration for the sample data is 0.097 cc

jonny [76]

Answer:

Step-by-step explanation:

Confidence interval is written in the form,

(Sample mean - margin of error, sample mean + margin of error)

The sample mean, x is the point estimate for the population mean.

Margin of error = z × s/√n

Where

s = sample standard deviation = 0.0074

n = number of samples = 27

From the information given, the population standard deviation is unknown and the sample size is small, hence, we would use the t distribution to find the z score

In order to use the t distribution, we would determine the degree of freedom, df for the sample.

df = n - 1 = 27 - 1 = 26

Since confidence level = 90% = 0.90, α = 1 - CL = 1 – 0.9 = 0.1

α/2 = 0.1/2 = 0.05

the area to the right of z0.05 is 0.05 and the area to the left of z0.05 is 1 - 0.05 = 0.95

Looking at the t distribution table,

z = 1.706

The critical value is 1.706

Margin of error = 1.706 × 0.0074√27

= 0.0024

The 90% confidence interval is

0.097 ± 0.0024

4 0

3 years ago

You invested $10,000 into two accounts: one that has a simple 3% interest, the other with 2.5% interest. If your total interest

artcher [175]

Answer:

3300 was on 3% and 6700 on 2,5%

Step-by-step explanation:

We can say that 'a' represents the price that will go on 3% interest and 'b' 2,5% interest.

Therefore;

a + b = 10 000

And

0,03a + 0,025b = 283.5 (0,03 means 3% etc)

You can move 'b' to the other side to leave 'a' on the LHS

0,03a = 283.5 - 0,025b - - > (divide both sides by 0,03)

a=9450 - 0,8333b

Substitute this equation as 'a' in the first equation to get:

9450 - 0,8333b + b = 10 000 (move 9450 to the RHS to leave values with b on the LHS)

-0,8333b + b = 10 000 - 9450

0,1666b = 550 (divide both sides by 0,1666)

b = 3,300

Therefore 'a' will be :

a= 10 000 - 3 300

a = 6700

I hope this helps.

4 0

3 years ago