What number should be added to the expression x2+6x to change it into a perfect square trinomial?

Mathematics

1 answer:

Trava [24]3 years ago

8 0

The answer is 9. x^2 + 6x + 9. You take 6/2, which is 3 then you would square it, which would give you 9.

You might be interested in

Among a sample of 55 male soldiers the average shower time was found to be 2.95 minutes and the population standard deviation is

Oksanka [162]

Answer: -3.0593

Step-by-step explanation:

The test statistic for the difference between two population mean (when population standard deviations $\sigma_1\ \&\ \sigma_2$ are known ) is given by :-

$z=\dfrac{\overline{x}_1-\overline{x}_2}{\sqrt{\dfrac{\sigma_1^2}{n_1}+\dfrac{\sigma_2^2}{n_2}}}$

where ,

$n_1\ \&\ n_2$ = Sample sizes taken from two populations 1 and 2.

$\overline{x}_1-\overline{x}_2$ = Difference between two Sample mean.

$\sigma_1\ \&\ \sigma_2$ = Standard deviations of populations 1 and 2.

As per given , we have

$n_1=55\ \&\ n_2=58$

$\overline{x}_1=2.95\ \&\ \overline{x}_2=3.3$

$\sigma_1=0.65\ \&\ \sigma_2=0.56$

We assume that the data follows a normal distribution.

Then, the test statistic will be :-

$z=\dfrac{2.95-3.3}{\sqrt{\dfrac{(0.65)^2}{55}+\dfrac{(0.56)^2}{58}}}\\\\=\dfrac{-0.35}{\sqrt{0.0130887}}\\\\=\dfrac{-0.35}{0.1144059}=3.05928278174\approx-3.0593$

Hence, the test statistic= -3.0593

5 0

4 years ago

Trevor solved the system of equations below. What mistake did he make in his work? 2x + y = 5 x − 2y = 10 y = 5 − 2x x − 2(5 − 2

Arturiano [62]

$2x+y=5 \\
x-2y=10 \\ \\
y=5-2x \\
x-2(5-2x)=10 \\
x-10+4x=10 \\
5x-10=10 \\
\boxed{5x=0} \Leftarrow \hbox{the mistake, it should be 5x=20} \\
x=0 \\ \\
2(0)+y=5 \\
y=5$

If 2x+y=5, then y=5-2x, so he substituted 5-2x correctly.
x+4x=5x, so he combined like terms correctly.
If 5x-10=10, then 5x=10+10 -> 5x=20, so he subtracted 10 from the right side instead of adding 10 to the right side.

The answer is C.

Here's the correct solution:
$2x+y=5 \\
x-2y=10 \\ \\
y=5-2x \\
x-2(5-2x)=10 \\
x-10+4x=10 \\
5x-10=10 \\
5x=10+10 \\
5x=20 \\
x=\frac{20}{5} \\
x=4 \\ \\
y=5-2x \\
y=5 - 2 \times 4 \\
y=5-8 \\
y=-3 \\ \\
(x,y)=(4,-3)$

5 0

3 years ago

Lesson 9: When Are They the Same?

marysya [2.9K]

Answer:

The number of pages that will make the cost of printing equal for both options is 500

Step-by-step explanation:

Please, kindly see the attached file for explanation