PLEASE HELP MEH RN!!!

Mathematics

2 answers:

nordsb [41]4 years ago

5 0

Answer:

its 4x

Step-by-step explanation:

Romashka [77]4 years ago

3 0

Answer:

Step-by-step explanation:

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Solve for x Write both solutions, seperated by a comma 4x^2+5x+1=0

stiv31 [10]

Answer:

-1/4 , -1

Step-by-step explanation:

I solved it using Factorization method and Quadratic Equation .

Factorization Method

$4x^2+5x+1=0\\Write +5x- as- a -difference(write+5x-using- two- numbers -in-which-their-sum-is ; 5-and-their-product-is ; 4)\\4x^{2} +4x+1x+1=0\\Factorize-out-common-terms\\4x(x+1)+1(x+1)=0\\Factor-out-(x+1)\\(4x+1)(x+1)=0\\4x+1 =0 \\x+1=0\\4x=0-1\\x =0-1\\4x =-1\\x =-1\\4x=-\frac{1}{4} \\\\Answer = -1/4 , -1$

Quadratic Equation

$4x^2+5x+1=0\\a = 4\\b =5\\c = 1\\\\x =\frac{-b\±\sqrt{b^2 -4ac} }{2a} \\\\x = \frac{-(5)\±\sqrt{(5)^2-4(4)(1)} }{2(4)} \\\\x = \frac{-5\±\sqrt{25-16} }{8} \\\\x = \frac{-5\±\sqrt{9} }{8} \\\\x = \frac{-5\±3}{8} \\\\x =\frac{-5+3}{8} \\\\x = \frac{-5-3}{8} \\\\x = \frac{-2}{8} \\\\x = \frac{-8}{8} \\\\x = -\frac{1}{4} \\x=-1$

5 0

3 years ago

On a standard IQ test, the standard deviation is 15. How many random IQ scores must be obtained if we want to find the true popu

igor_vitrenko [27]

Answer:

We need at least 4238 scores.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.97}{2} = 0.015$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.015 = 0.985$ , so $z = 2.17$

Now, find the margin of error M

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

How many random IQ scores must be obtained if we want to find the true population mean (with an allowable error of 0.5) and we want 97 percent confidence in the results

We need at least n scores, in which N is found when $M = 0.5$ . So