What should you do first in solving this equation?<br> x2 + 6x

Find the squares of (y+3)

emmasim [6.3K]

Answer:

Since we know that

(a+b)

2

=a

2

+2ab+b

2

(a−b)

2

=a

2

−2ab+b

2

Now,

(i)

(x+3y)

2

=x

2

+2×x×3y+(3y)

2

=x

2

+6xy+9y

2

(ii)

(2x−5y)

2

=(2x)

2

−2×2x×5y+(5y)

2

=4x

2

−20xy+25y

2

(iii)

(a+

5a

1

)

2

=a

2

+2×a×

2a

1

+(

2a

1

)

2

=a

2

+1+

4a

2

1

(iv)

(2a−1a)=(1a)

2

(1a)

2

=1a

2

Answer

8 0

3 years ago

Factor the four-term polynomial ab + ac - 4b - 4c

Troyanec [42]

A b + a c - 4 b - 4 c = a ( b + c ) - 4 ( b + c ) =
= (b + c) (a - 4)

5 0

3 years ago

Please help! Only answer if you know how to do it.

Mashutka [201]

Your answer would 699.3 that is it

7 0

3 years ago

Life rating in Greece. Greece has faced a severe economic crisis since the end of 2009. A Gallup poll surveyed 1,000 randomly sa

elena-s [515]

Answer:

a

The population parameter of interest is the true proportion of Greek who are suffering

While the point estimate of this parameter is proportion of those that would rate their lives poorly enough to be considered "suffering". which is 25%

b

The condition is met

c

The 95% confidence interval is $0.223 < p < 0.277$

d

If the confidence level is increased which will in turn reduce the level of significance but increase the critical value( $Z_{\frac{\alpha }{2} }$ ) and this will increase the margin of error( deduced from the formula for margin of error i.e $E \ \alpha \ Z_{\frac{\alpha }{2} }$ ) which will make the confidence interval wider

e

Looking at the formula for margin of error if the we see that if the sample size is increased the margin of error will reduce making the confidence level narrower

Step-by-step explanation:

From the question we are told that

The sample size is n = 1000

The population proportion is $\r p = 0.25$

Considering question a

The population parameter of interest is the true proportion of Greek who are suffering

While the point estimate of this parameter is proportion of those that would rate their lives poorly enough to be considered "suffering". which is 25%

Considering question b

The condition for constructing a confidence interval is

$n * \r p > 5\ and \ n(1 - \r p ) >5$

So

$1000 * 0.25 > 5 \ and \ 1000 * (1-0.25 ) > 5$

$250 > 5 \ and \ 750> 5$

Hence the condition is met

Considering question c

Given that the confidence level is 95% then the level of significance is mathematically evaluated as

$\alpha = 100 - 95$

$\alpha = 5 \%$

$\alpha = 0.05$

Next we obtain the critical value of $\frac{\alpha }{2}$ from the normal distribution table, the value is

$Z_{\frac{\alpha }{2} } = 1.96$

Generally the margin of error is mathematically represented as

$E = Z_\frac{ \alpha }{2} * \sqrt{ \frac{\r p (1 - \r p ) }{n} }$

substituting values

$E = 1.96 * \sqrt{ \frac{ 0.25 (1 - 0.25 ) }{ 1000} }$

$E = 0.027$

The 95% confidence interval is mathematically represented as

$\r p - E < p < \r p + E$

substituting values

$0.25 - 0.027 < p < 0.25 + 0.027$

substituting values

$0.223 < p < 0.277$

considering d

If the confidence level is increased which will in turn reduce the level of significance but increase the critical value( $Z_{\frac{\alpha }{2} }$ ) and this will increase the margin of error( deduced from the formula for margin of error i.e $E \ \alpha \ Z_{\frac{\alpha }{2} }$ ) which will make the confidence interval wider

considering e

Looking at the formula for margin of error if the we see that if the sample size is increased the margin of error will reduce making the confidence level narrower

5 0

3 years ago

The public library has to move 42,000 books to its new location. The movers can pack an average of 45 books in every box. The tr

Anni [7]

Answer:

<h2> 934boxes</h2><h2> 4 trips</h2>

Step-by-step explanation:

Given the total number of books 42,000

Ok, firstly let us calculate the number of boxes required, given that a box can contain 45 books

number of boxes= 42,000/45

number of boxes=933.3 boxes

approximately 934boxes

Also, given that the truck can carry online 250 boxes in one trip

then it must make 934/250= 3.7 trips

approximately the truck will make 4 trips to carry all the boxes

7 0

4 years ago

What should you do first in solving this equation? x2 + 6x - 13 = 3