Please help. I will give out brainliest

OverLord2011 [107]

Answer:

$\large\boxed{x=-3\ and\ y=-11\to(-3,\ -11)}$

Step-by-step explanation:

$\underline{+\left\{\begin{array}{ccc}-6x+y=7\\3x-y=2\end{array}\right}\qquad\text{add both sides of the equations}\\\\.\qquad-3x=9\qquad\text{divide both sides by (-3)}\\.\qquad\boxed{x=-3}\\\\\text{Put the value of x to the first equation:}\\\\-6(-3)+y=7\\18+y=7\qquad\text{subtract 18 from both sides}\\\boxed{y=-11}$

3 0

3 years ago

Solve 2x2 + 12x - 14 = 0 by completing the square

vovangra [49]

Answer:

Step-by-step explanation:

$(a+b)^2=a^2+2ab+b^2\qquad(*)\\\\\\2x^2+12x-14=0\qquad\text{divide both sides by 2}\\\\x^2+6x-7=0\qquad\text{add 7 to both sides}\\\\x^2+2(x)(3)=7\qquad\text{add}\ 3^2=9\ \text{to both sides}\\\\\underbrace{x^2+2(x)(3)+3^2}_{(*)}=7+9\\\\(x+3)^2=16\Rightarrow x+3=\pm\sqrt{16}\\\\x+3=-4\ or\ x+3=4\qquad\text{subtract 3 from both sides}\\\\x=-7\ or\ x=1$

5 0

4 years ago

Solve this equation 3x - 5 = -26

Dmitry_Shevchenko [17]

3x - 5 = -26

step 1:

subtract +5 on each side because you have to do the inverse operation

step 2:

3x= -21

step 3:

now divide 3 on each side

the answer is -7

Hope this helped!

TheOneAndOnlyLara~

5 0

2 years ago

Read 2 more answers

Find the value of x. B х 8 A 3 D 4 x = [?] Enter

omeli [17]

Answer:

X=6

Step-by-step explanation:

If B and C equal 8 and is larger than x than x is a smaller number. D and C is 4 but its smaller than x so x has to be bigger. Your left with 3 choices 5, 6, and 7. Measure it and find out how big x is and its between 6 or 7. If any means they do decimals it can also be 6.5 so x=6 or x=7 or x=6.5

4 0

3 years ago

2. A marketing firm is trying to estimate the proportion of potential car buyers that would consider

Maurinko [17]

Answer:

a. The number of people that should be in the pilot study are 600 people

b. The point estimate is 0.62 $\overline 6$

c. At 95% confidence level the true population proportion of potential car buyers of hybrid vehicle is between the confidence interval (0.588, 0.6654)

d. Two ways to reduce the margin of error are;

1) Reduce the confidence interval

2) Use a larger sample size

Step-by-step explanation:

a. The given parameters for the estimation of sample size is given as follows;

The margin of error for the confidence interval, E = 4% = 0.04

The confidence level = 95%

The sample size formula for a proportion as obtained from an online source is given as follows;

$n = \dfrac{Z^2 \times P \times (1 - P)}{E^2}$

Where, P is the estimated proportions of the desired statistic, therefore, we have for a new study, P = 0.5;

Z = The level of confidence at 95% = 1.96

n + The sample size

Therefore, we have;

$n = \dfrac{1.96^2 \times 0.5 \times (1 - 0.5)}{0.04^2} = 600.25$

Therefore, the number of people that should be in the pilot study in order to meet this goal at 95% confidence level is n = 600 people

b. The point estimate for the population proportion is the sample proportion given as follows;

$\hat p = \dfrac{x}{n}$

Where;

x = The number of the statistic in the sample

n = The sample size

From the question, we have;

The number of potential car buyers, n = 600

The number of respondent in the sample that indicated that they would consider purchasing a hybrid, x = 376

Therefore, the point estimate, for the proportion of potential car buyers that would consider buying a hybrid vehicle, $\hat p$ = 376/600 = 0.62 $\overline 6$