All categories

3 years ago

What number would you add to the equation below to complete the square?x2 + 4x = 0?

1 answer:

7 0

------------------------------------------------------------------
Equation
------------------------------------------------------------------
x² + 4x = 0

------------------------------------------------------------------
Add a constant
------------------------------------------------------------------
x² + 4x + (4/2)² - (4/2)² = 0 ← Add 2² to form perfect square

------------------------------------------------------------------
Evaluate bracket
------------------------------------------------------------------
x² + 4x + 2² - 2² = 0

------------------------------------------------------------------
Form the perfect square
------------------------------------------------------------------
(x + 2)² = 4

------------------------------------------------------------------
Square root both sides
------------------------------------------------------------------
(x+2) = $\pm$ √4

------------------------------------------------------------------
Evaluate the square root
------------------------------------------------------------------
(x+2) = $\pm$ 2

------------------------------------------------------------------
Solve x
------------------------------------------------------------------
x = 2 - 2 or x = -2 - 2

x = 0 or -4

------------------------------------------------------------------
Answer: The constant to add is 4 and the value of x = 0 or -4
------------------------------------------------------------------

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Answer:

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3 years ago

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2 years ago

A consumer testing service tested whether the average baking time of whole wheat bread in gas ovens was less than the average ba

vichka [17]

Answer:

Part 1) The explanatory variable is the type of oven

It is a categorical variable

Part 2) The response variable is the baking time

It is a quantitative variable

part 3) two-sample z-test for proportions should be used for the test

Step-by-step explanation:

An explanatory variable is an independent variable that is not affected by all other variables. In this experiment, the type of oven is the input variable and it is not affected by any other variable

A categorical variable is one that has two or more categories without any intrinsic ordering of the categories. The type of oven is either gas or electric, so it is categorical.

A response variable is a dependent variable whose variation depends on other variables. The baking time in this experiment depends on the type of oven used

A quantitative variable is one that take on numerical values.

A two proportion z-test allows you to compare two proportions to see if they are the same. The null hypothesis (H0) for the test is that the proportions are the same. The alternate hypothesis (H1) is that the proportions are not the same.

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3 years ago

Does the given value make the inequality true? x + 9 > 21, when x = 15

Verizon [17]

Answer:

yes, the inequality is true.

Step-by-step explanation:

15 + 9 = 24

24 > 21

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3 years ago

Please help! can you explain it to me?

Semenov [28]

Answer:

It is increasing before x = -2 and from x = 0 to x = 2

Step-by-step explanation:

Option 1 - you can see the line going down starting at -2 and that means the line is decreasing but the choice says "It is increasing before x = 0". This contradicts the actual graph.

Option 2 - The line isn't increasing before x= -1, it's actually decreasing as seen in the graph.

Option 3 - The line doesn't even touch the point before x = -3 so this choice makes no sense.

Option 4 - Since all the other choices were eliminated this is the only choice standing. Looking at the line it is increasing before x = -2.

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2 years ago