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3 years ago

3 4 (2a − 6) + 1 2 = 2 5 (3a + 20) what's the answer for a?

Mathematics

2 answers:

julsineya [31]3 years ago

4 0

The answers for A equals to 4.57

aivan3 [116]3 years ago

3 0

Answer:

Step-by-step explanation:

a=4.57

You might be interested in

P(x)= 3x^3-5x^2-14x-4

nexus9112 [7]

$\displaystyle\\
P(x)=3x^3-5x^2-14x-4\\\\
D_{-4}=\{-4;~-2;~\underline{\bf -1};~1;~2;~4\}\\\\
\text{We observe that } \frac{-1}{3} \text{ is a solution of the equation:}\\
3x^3-5x^2-14x-4=0\\\\
$

$\displaystyle\\
\text{Verification}\\\\
3x^3-5x^2-14x-4=\\\\
=3\times\Big(-\frac{1}{3}\Big)^3-5\times\Big(-\frac{1}{3}\Big)^2-14\times\Big(-\frac{1}{3}\Big)-4=\\\\
=-\frac{1}{9}-\frac{5}{9}+\frac{14}{3}-4=\\\\
=-\frac{6}{9}+\frac{14}{3}-4=\\\\
=-\frac{6}{9}+\frac{42}{9}- \frac{4\times 9}{9}=\\\\
 =-\frac{6}{9}+\frac{42}{9}- \frac{36}{9}= \frac{42-6-36}{9}=\frac{42-42}{9}=\frac{0}{9}=0\\\\
\Longrightarrow~~~P(x)~\vdots~\Big(x+ \frac{1}{3}\Big)\\\\
\Longrightarrow~~~P(x)~\vdots~(3x+1)$

$\displaystyle\\
3x^3-5x^2-14x-4=0\\
~~~~~-5x^2 = x^2 - 6x^2\\
~~~~~-14x =-2x-12x \\
3x^3+x^2 - 6x^2-2x-12x-4=0\\
x^2(3x+1)-2x(3x+1) -4(3x+1)=0\\
(3x+1)(x^2-2x -4)=0\\\\
\text{Solve: } x^2-2x -4=0\\\\
x_{12}= \frac{-b\pm \sqrt{b^2-4ac}}{2a}=\\\\=\frac{2\pm \sqrt{4+16}}{2}=\frac{2\pm \sqrt{20}}{2}=\frac{2\pm 2\sqrt{5}}{2}=1\pm\sqrt{5}\\\\
x_1 =1+\sqrt{5}\\
x_2 =1-\sqrt{5}\\
\Longrightarrow P(x)= 3x^3-5x^2-14x-4 =\boxed{(3x+1)(x-1-\sqrt{5})(x-1+\sqrt{5})}$

7 0

2 years ago

What is the value of x in the equation x - y = 30, when y = 15?<br> O4<br> O 8<br> O 80<br> O 200

olganol [36]

$\frac{1}{5}x - \frac{2}{3} y = 30 \\$

Putting the value of Y = 15

$\frac{1}{5} x - \frac{2}{3} \times 15 = 30 \\ \frac{1}{5} x = 30 + 10 \\ \frac{1}{5} x = 40 \\ x = 5 \times 40 \\ x = 200$

So, X = 200

6 0

2 years ago

In a national survey of 1987 adults, 1570 responded that lack of respect and courtesy in American society is a serious problem,

Alik [6]

<h2>Answer with explanation:</h2>

As per given , we have

$H_0: p\leq\dfrac{3}{4}\\\\H_a: p>\dfrac{3}{4}$

Since , alternative hypothesis is right tailed, so the test is a right tailed test.

n= 1987

Proportion of adults believe that rudeness is a worsening problem : $p=\dfrac{1257}{1987}\approx 0.6326$

Test statistic : $z=\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}}$

$z=\dfrac{ 0.6326-0.75}{\sqrt{\dfrac{0.75(1-0.75)}{1987}}}=-12.09$

(since , the normal curve takes values of z from -7 to 7, so we use critical value to draw conclusion.)

The critical value for a significance level of 0.005= 1.645

Since , absolute test statistic value (12.09) is greater than the critical value (1.645), it means there is statistical significance and so we reject the null hypothesis.

3 0

3 years ago

Find the y-intercept of 2x - 3y = 6

Ksju [112]

Answer:

(0, - 2)

Step-by-step explanation:

The y-intercept is the value of y when x = 0. Substitute 0 for x in the equation and solve for y.

$2x - 3y = 6$