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2 years ago

Which of the following number lines and solution sets show the values of r that make the inequality -2r+3<9 true

Mathematics

1 answer:

scoray [572]2 years ago

4 0

Answer:

"Solving'' an inequality means finding all of its solutions. A "solution'' of an inequality is a number which when substituted for the variable makes the inequality a true statement. When we substitute 8 for x, the inequality becomes 8-2 > 5. Thus, x=8 is a solution of the inequality.

Step-by-step explanation:

Example 1:

Consider the inequality

displaymath173

The basic strategy for inequalities and equations is the same: isolate x on one side, and put the "other stuff" on the other side. Following this strategy, let's move +5 to the right side. We accomplish this by subtracting 5 on both sides (Rule 1) to obtain

displaymath174

after simplification we obtain

displaymath175

Once we divide by +2 on both sides (Rule 3a), we have succeeded in isolating x on the left:

displaymath176

or simplified,

displaymath177

All real numbers less than 1 solve the inequality. We say that the "set of solutions'' of the inequality consists of all real numbers less than 1. In interval notation, the set of solutions is the interval tex2html_wrap_inline187 .

Example 2:

Find all solutions of the inequality

displaymath189

Let's start by moving the ``5'' to the right side by subtracting 5 on both sides (Rule 1):

displaymath190

or simplified,

displaymath191

How do we get rid of the ``-'' sign in front of x? Just multiply by (-1) on both sides (Rule 3b), changing " tex2html_wrap_inline201 " to " tex2html_wrap_inline203 " along the way:

displaymath192

or simplified

displaymath193

All real numbers greater than or equal to -1 satisfy the inequality. The set of solutions of the inequality is the interval tex2html_wrap_inline205 .

Example 3:

Solve the inequality

displaymath207

Let us simplify first:

displaymath208

There is more than one route to proceed; let's take this one: subtract 2x on both sides (Rule 1).

displaymath209

and simplify:

displaymath210

Next, subtract 9 on both sides (Rule 1):

displaymath211

simplify to obtain

displaymath212

Then, divide by 4 (Rule 3a):

displaymath213

and simplify again:

displaymath214

It looks nicer, if we switch sides (Rule 2).

displaymath215

In interval notation, the set of solutions looks like this: tex2html_wrap_inline227 .

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Determine the missing number in each sequence

snow_tiger [21]

You can't determine that unless you are given the sequence. of course you can infer about it and is easy but mathematically, there are an infinite number or sequences with these terms but u need the sequence

7 0

3 years ago

)) a. Write three side lengths that will

Zolol [24]

Answer:

3,4,5 forms a right triangle

1,2 ,9 does not form a triangle

Step-by-step explanation:

Three side lengths that will form a triangle

3,4,5

This is a Pythagorean triple. It forms a right triangle

3^2 +4^2 = 5^2

9+16=25

25=25

Three side lengths that will not form a triangle

1,2 9

The sum of the two smaller sides must be greater then the third

1+2 < 9 not greater

3 0

3 years ago

Read 2 more answers

Students are given 3 minutes to complete each multiple-choice question on a test and 8 minutes for each free-response question.

SpyIntel [72]

Let

x------> the number of multiple choice question

y------> the number of free response question

we know that

$3x+8y=55$ -----> equation A

$x+y=15$

$x=15-y$ -----> equation B

Substitute equation B in equation A

$3[15-y]+8y=55$

$45-3y+8y=55$

$5y=55-45$

$5y=10$

$y=2$

Find the value of x

$x=15-y$

$x=15-2=13$

therefore

<u>the answer is</u>

the number of multiple choice question are $13$

the number of free response question are $2$

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3 years ago

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It costs $4.25 per game at the bowling alley, plus $1.90 to rent shoes. If Wayne has $20, how many games can he bowl?

Natasha2012 [34]

Answer:

Step-by-step explanation:

4 games

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3 years ago

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How to factor 6n2 - 6n - 12

alexandr402 [8]

We see that in these 3 terms, 6 is a common factor. So, let's factor out a 6:

$6n^2-6n-12 = 6(n^2-n-2)$

We can set this equal to 0 and factor by using the quadratic formula which is:

$x = \frac{-b \pm \sqrt{b^2-4ac} }{2a}$

So, let's do just that:

$6(n^2-n-2) = 0$

Note that the 6 goes away if you divide both sides by 6. In this case, a = 1, b = -1, and c = -2. Let's plug that into the quadratic equation:

$\frac{1 \pm \sqrt{(-1)^2-4(1)(-2)} }{2(1)} = \frac{-1 \pm \sqrt{1-(-8)} }{2}$

$\frac{-1 \pm \sqrt{9} }{2} = {1, -2}$

So, we can write this as:

$6n^2 - 6n - 12 = 6(n-1)(n+2)$

Notice that the 6 comes back because it was only temporarily mad. And that the roots have opposite signs in the parentheses because to find the roots, you need to set each parentheses equal to 0 and solve for n. With that in mind, your final answer is 6(n-1)(n+2). Hope I could help you!

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