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3 years ago

The line passing through the point (-2,5)and (1,a) is perpendicular to the line 2x-y-5=0, find the value of a

Mathematics

1 answer:

timofeeve [1]3 years ago

8 0

Answer:

a = 7/2

Step-by-step explanation:

2x - y - 5 = 0

2x = y + 5

y = 2x - 5

m = -1/2

y - 5 = -1/2(x - (-2))

y - 5 = -1/2(x + 2)

y - 5 = -x/2 - 1

y = -x/2 + 4

a = -1/2 + 4

a = 7/2

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Starter

4vir4ik [10]

Answer:

1) £2 = €2.32

£5 = €5.80

£50 = €58

2) The graph will be a straight line

3) (0, 0)

4) Label the independent variable, £ on the x-axis and dependent variable € on the y-axis

Step-by-step explanation:

1) The given conversion factors is £1 = €1.16

Therefore;

£2 = 2 × €1.16 = €2.32

£2 = €2.32

£5 = 5 × €1.16 = €5.80

£5 = €5.80

£50 = 50 × €1.16 = €58

£50 = €58

2) The shape of the plot of the directly proportional currencies graph will be a straight line

3) Given that the £ is directly proportional to the € and that the value of the € can be found directly by multiplying the amount in £ by 1.16, without the addition of a constant, the graph crosses the axes at the origin (0, 0)

4) The y-axes which is the dependent variable should be labelled €, while the x-axis which is the independent variable should be labelled £

4 0

3 years ago

NEED HELP IMMEDIATELY. I WILL BRAINLIEST. NEED TO SOLVE FOR X INTERCEPT

Kay [80]

Answer:

(1+√7,0),(1−√7,0)

Step-by-step explanation:

You can't factor the expression evenly, so use the quadratic formula.

a = 2

b= -4

c= -12

$\frac{-b+\sqrt{b^{2}-4ac } }{2a}$

$\frac{4+\sqrt{16{}-4(2)(-12)} }{2(2)}$

$\frac{4+\sqrt{16-4(-24)} }{4}$

$\frac{4+\sqrt{16+96} }{4}$

$\frac{4+\sqrt{112} }{4}$

$\sqrt{112} = 4\sqrt{7}$

End result: (1+√7,0),(1−√7,0)

5 0

3 years ago

Show all your work to receive full credit for this problem. Solve the system of equations using the elimination method. 2a + 3b

Sindrei [870]

Given equations are;
2a + 3b = -1 ..................equation 1
3a + 5b = -2 ....................equation 2

Now multiply equation 1 with (-3)

The equation will be;

-6a -9b = 3 …………………..equation 3

Now multiply equation 2 with (2)

The equation will be;

6a + 10b = -4 ……………..equation 4

Now add equation 3 and equation 4

-6a – 9b = 3

6a + 10b = -4

------------------------------

0a + b = -1

b = -1

Now put the value of b in equation 1

2a + 3(-1) = -1

2a -3 = -1

2a = -1+3

2a = 2

a=1

Thus the solution is (a,b) = (1,-1)

8 0

3 years ago

Sarah claims that the thickness of the spearmint gum she produces is 7.5 one-hundredths of an inch. A quality control specialist

satela [25.4K]

Answer:

$t=\frac{7.55-7.5}{\frac{0.103}{\sqrt{10}}}=1.539$

$p_v =2*P(t_{(9)}>1.539)=0.158$

If we compare the p value and the significance level assumed $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis.

Step-by-step explanation:

Data given and notation

Data: 7.65, 7.60, 7.65, 7.7, 7.55, 7.55, 7.4, 7.4, 7.5, 7.5

We can begin calculating the sample mean given by:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

And the sample deviation given by:

$s=\sart{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

And we got:

$\bar X=7.55$ represent the sample mean

$s=0.103$ represent the sample standard deviation

$n=10$ sample size

$\mu_o =7.5$ represent the value that we want to test

$\alpha=0.05$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is equal to 7.5 or no, the system of hypothesis would be:

Null hypothesis: $\mu = 7.5$

Alternative hypothesis: $\mu \neq 7.5$

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{7.55-7.5}{\frac{0.103}{\sqrt{10}}}=1.539$

P-value

The first step is calculate the degrees of freedom, on this case:

$df=n-1=10-1=9$

Since is a two sided test the p value would be:

$p_v =2*P(t_{(9)}>1.539)=0.158$

Conclusion

If we compare the p value and the significance level assumed $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis.

3 0

4 years ago

Write -4i+(1/4-5i)-(-3/4+8i)+17i as a complex number in the standard for

KatRina [158]

Answer:

$1+ 0i$

Step-by-step explanation:

A complex number is a number which has some real part and some imaginary part.

Standard form of a complex number is represented as

$a +bi$

Where $a$ is the real part,

and $bi$ is the imaginary part.

And $i = \sqrt{-1}$

Given complex number:

$-4i+\dfrac{1}{4}-5i)-(-\dfrac{3}{4}+8i)+17i\\\Rightarrow -4i+\dfrac{1}{4}-5i + \dfrac{3}{4}-8i+17i\\\Rightarrow \dfrac{3}{4}+\dfrac{1}{4}-4i -5i-8i+17i\\\Rightarrow \dfrac{3+1}{4}-17i+17i\\\Rightarrow \dfrac{4}{4}+0i\\\Rightarrow 1 + 0i$

Hence, the standard form is $1+ 0i$ .

8 0

3 years ago

The line passing through the point (-2,5)and (1,a) is perpendicular to the line 2x-y-5=0, find the value of a​

The line passing through the point (-2,5)and (1,a) is perpendicular to the line 2x-y-5=0, find the value of a