All categories

4 years ago

13. Solve: 3x² +11x +5<9

Mathematics

1 answer:

SashulF [63]4 years ago

6 0

Answer:

-4<x<1/3

Step-by-step explanation:

3x²+11x+5<9

3x²+11x-4<0.

First we determine the solutions of

3x²+11x-4=0

Delta=11²-4×3×(-4)=121+48=169=13²

The roots are

x1=(-11-13)/6=-24/6=-4

x2=(-11+13)/6=2/6=1/3

So, we have:

3x²+11x-4=3(x-⅓)(x+4)=(3x-1)(x+4)

So, coming back to our inequality:

(3x-1)(x+4)<0, we note (as we already know) that this condition is satisfied for all those x located between the roots: -4<x<1/3

You might be interested in

Kyle has $1500 to invest in a saving's account for 5 years. He has 3 options:

Snezhnost [94]

Answer:

bank c

Step-bby-step explanation:

It's obvious that compound interest will give you more money than simple and therefore we can eliminate bank A

It's best to have your interest compounding as often as possible and because that's the only difference between bank B and C bank C is the best

4 0

3 years ago

What is the value expression to 3 1/4 - 1 7/8 =show how?

Andrei [34K]

3 1/4 - 1 7/8
First, subtract the whole numbers (3 - 1 = 2):
= 2 1/4 - 7/8
Convert 1/4 to 2/8:
= 2 2/8 - 7/8
Borrow 1=8/8 from the 2:
= 1 10/8 - 7/8
Subtract 7/8 from 10/8:
= 1 3/8

The answer is 1 3/8

Alternatively, use improper fractions:
3 1/4 = 13/4 = 26/8
1 7/8 = 15/8
26/8 - 15/8 = 11/8 = 1 3/8

3 0

3 years ago

What's the probability of the compound event for. A bag contains 4 red, 8 blue, 6 yellow and 2 green marbles. Maria selects a ma

Nataly [62]

Given:

Number of red marbles = 4

Number of blue marbles = 8

Number of yellow marbles = 6

Number of green marbles = 2

To find:

The probability of getting a blue marble then a red marble, i.e., P(blue, red).

Solution:

Using the given information,

The total number of marbles = 4+8+6+2

= 20

Probability of getting a blue marble in first draw is

$P(Blue)=\dfrac{\text{Number of blue marbles}}{\text{Total number of marbles}}$

$P(Blue)=\dfrac{8}{20}$

$P(Blue)=\dfrac{2}{5}$

Maria selects a marble, puts it back and then selects a second marble. It means the total number of marbles remains the same.

$P(red)=\dfrac{\text{Number of red marbles}}{\text{Total number of marbles}}$

$P(red)=\dfrac{4}{20}$

$P(red)=\dfrac{1}{5}$

Now, the probability of getting a blue marble then a red marble is

$P(blue,red)=\dfrac{2}{5}\times \dfrac{1}{5}$

$P(blue,red)=\dfrac{2}{25}$

Therefore, the required probability P(blue, red) is $\dfrac{2}{25}$ .

5 0

3 years ago

Can u answer this please?

denpristay [2]

2. 2 increasing
3. Y=-x +9 decreasing
4. 2 increasing
5. 6 increasing
6. Y=-3x+1 decreasing

5 0

2 years ago

The math test has 10 multiple choice questions, each with 4 answers. If Betty guesses correctly on the first 2 questions, what i

bekas [8.4K]

<span>It doesn't matter that she guessed correctly on the first two questions, guessing the third question correctly is independent of guessing any other question correctly. Therefore, the probability is one out of four, 1/4.</span>

5 0

3 years ago

Read 2 more answers