All categories

3 years ago

Solve the quadratic equation by completing the square. x2 + 4x - 3 = 0

1 answer:

6 0

First move the constant to the other side of the equation by adding 3 to both sides...

x^2+4x=3

Now halve the linear coefficient, 4/2=2, square it, 2^2=4, and add that value to both sides...

x^2+4x+4=7, now the left side is a perfect square of the form...

(x+2)^2=7, now take the square root of both sides...

x+2=±√7, subtract 2 from both sides...

x=-2±√7

So x=-2-√7 and -2+√7

You might be interested in

The figure below is a scale drawing of Quinto's bedroom. The scale used to create the drawing is 1/2 inch = 4 feet. What is the

Nezavi [6.7K]

We know that

the scale is is 1/2 inch = 4 feet

using a graph tool
the approximate measurements in the drawing are
5 cm x 4 cm
convert to in
5/2.54--------> 1.97 in
4/2.54------> 1.57 in

convert drawing to actual
if 0.5 in---------> 4 ft
1.97in-------> X
X=1.97*4/0.5------> X=15.76 ft

if 0.5 in---------> 4 ft
1.57 in-------> X
X=1.57*4/0.5------> X=12.56 ft

the approximate area of Quinto's bedroom is 12.56*15.76=197.95 ft²

the answer is
the option C)192 ft²

6 0

3 years ago

Plz need help for a grade god explanation and answer get brainliest

Ivanshal [37]

Answer:

20%

Step-by-step explanation:

There is a 20% chance you get selected for researching China because 5 out of 25 spaces are ones for researching China.

$\frac{5}{25} =\frac{20}{100}$

3 0

2 years ago

Find the slope of the line going through the point (1,2) and (0,8).

shtirl [24]

Answer:

The slope of the line is -6

Step-by-step explanation:

6 0

3 years ago

A phone manufacturer wants to compete in the touch screen phone market. He understands that the lead product has a battery life

Tasya [4]

Answer:

(a) H₀: μ ≤ 10. vs. Hₐ: μ > 10.

(b) The test statistic value is 1.86.

(d) The battery life of the new touch screen phone is not more than 10 hours.

Step-by-step explanation:

In this case we need to determine the significance of the claim made by the phone manufacturer, that the battery life of the new touch screen phone is more than twice as long as that of the leading product.

The information provided is:

$\bar x=10.5\\s=1.8\\n=45$

(a)

The hypothesis can be defined as follows:

H₀: The battery life of the new touch screen phone is not more than 10 hours, i.e. μ ≤ 10.

Hₐ: The battery life of the new touch screen phone is more than 10 hours, i.e. μ > 10.

(b)

As the population standard deviation is not provided, we will use a t-test for single mean.

Compute the test statistic value as follows:

$t=\frac{\bar x-\mu}{s/\sqrt{n}}=\frac{10.5-10}{1.8/\sqrt{45}}=1.86$

The test statistic value is 1.86.

(c)

The significance level of the test is, α = 0.10.

The degrees of freedom will be:

$df=n-1=45-1=44$

Compute the critical value as follows:

$t_{0.10, 44}=1.301$

*Use a t-table for the value.

Thus, the critical value to test the phone manufacturer's claim is 1.301.

(d)

Decision rule:

If the test statistic value is less than the critical value then the null hypothesis will be rejected and vice-versa.

t = 1.86 > t₀.₁₀, ₄₄ = 1.30

The calculated t-value of the test is more than the critical value.

The null hypothesis will not be rejected.

Thus, it can be concluded that the battery life of the new touch screen phone is not more than 10 hours.

6 0

2 years ago

Area of square tile, math question

Inessa05 [86]

Answer:

Answer: √49

___________

√49 = 7

Step-by-step explanation:

The area of a square is equal to the square of its side or the product of its side and its side.

A = s², because the sides of a square are congruent.

5 0

3 years ago