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3 years ago

Can somebody help me with this?

Mathematics

1 answer:

icang [17]3 years ago

7 0

We are given polynomial: $5x^3+8x^2-7x-6$ .

We need to explain why the binomial (x + 2) IS a factor of this polynomial expression and why the binomial (x + 1) IS NOT a factor of this polynomial expression.

Let us set first factor equal to 0 and solve for x.

x+2=0

x=-2.

Plugging x=-2 in given polynomial, we get

$5(-2)^3+8(-2)^2-7(-2)-6 = 5(-8) +8(4)+14-6$

$= -40 +32+14-6$

$=0$

Because x=-2 gives 0 on plugging in given polynomial, so it's factor of given polynomial expression.

Now, let us check second factor x+1=0

x=-1.

Plugging x=-1 in given polynomial, we get

$5(-1)^3+8(-1)^2-7(-1)-6 = 5(-1) +8(1)+7-6$

=-5+8+7-6.

= -4.

Because x=-1 doesn't gives 0 on plugging in given polynomial, so it's not a factor of given polynomial expression.

You might be interested in

Alvin is 7 years younger than Elgas. The sum of their ages is 63. What is Elgas age?

Elden [556K]

Answer:

Elgas is 35.

Step-by-step explanation:

Let's set up an equation.

Alvin is 7 years younger than Elgas.

A = E - 7

The sum of their ages is 63.

A + E = 63

Let's use substitution.

Plug in the first equation of A into the second equation.

A + E = 63

(E - 7) + E = 63

Combine like terms.

2E - 7 = 63

Add 7 to both sides.

2E = 70

Divide both sides by 2.

E = 35

Elgas is 35.

Hope this helps!

6 0

3 years ago

What's the next number? 0 , 1/3 , 1/2 , 3/5 , 2/3

madam [21]

Answer:

The next number of the series 0, 1/3, 1/2, 3/5, and 2/3 is 5/7

Step-by-step explanation:

The given numbers are;

0, 1/3, 1/2, 3/5, and 2/3

The number sequence is formed adding $\dfrac{1}{\left (\dfrac{n^2 + n}{2} \right ) }$ to each (n - 1)th term to get the nth term number in the sequence, with the first term equal to 0, as follows;

For the 2nd term, the (n - 1)th term is 0, and n = 2, gives;

The

$0 +\dfrac{1}{\left (\dfrac{2^2 + 2}{2} \right ) } = 0 + \dfrac{1}{3} = \dfrac{1}{3}$

For the 3rd term, the (n - 1)th term is 1/3, and n = 3, gives;

$\dfrac{1}{3} +\dfrac{1}{\left (\dfrac{3^2 + 3}{2} \right ) } = \dfrac{1}{3} + \dfrac{1}{6} = \dfrac{1}{2}$

For the 4th term, the (n - 1)th term is 1/2, and n = 4, gives;

$\dfrac{1}{2} +\dfrac{1}{\left (\dfrac{4^2 + 4}{2} \right ) } = \dfrac{1}{2} + \dfrac{1}{10} = \dfrac{3}{5}$

For the 5th term, the (n - 1)th term is 3/5, and n = 5, gives;

$\dfrac{3}{5} +\dfrac{1}{\left (\dfrac{5^2 + 5}{2} \right ) } = \dfrac{3}{5} + \dfrac{1}{15} = \dfrac{2}{3}$

For the next or 6th term, the (n - 1)th term is 2/3, and n = 6, gives;

$\dfrac{2}{3} +\dfrac{1}{\left (\dfrac{6^2 + 6}{2} \right ) } = \dfrac{2}{3} + \dfrac{1}{21} = \dfrac{15}{21} = \dfrac{5}{7}$

The next number of the series 0, 1/3, 1/2, 3/5, and 2/3 = 5/7.

6 0

3 years ago

Plz tell me how u got it and hurry please

Studentka2010 [4]

Because the shape is a cube, we know that all sides must be 5cm. To find the area of a side, you do base × height, so 5 × 5 = 25. If you look at the net, you'll notice that there are 6 faces, which means you have to do 25 × 6 = 150cm^2. I hope this helps!

8 0

3 years ago

Tshepo needs R5 000 urgently. He goes to the bank and borrows the money at an interest rate of 28% per annum, compounded monthly

12345 [234]

Answer:

R8000.

Step-by-step explanation:

First, let's calculate the amount they are going to have to pay the bank after 1 year. It is given by the following expression:

R5 000 * 1.28= R6400

Therefore, they have to pay R6400/12 monthly.

Now, in fifteen months the total amount to pay should be (R6400/12) * 15= R8000.

8 0

2 years ago

2 over 5 blank over 10 which is 0.4 in decimal form.

Tomtit [17]

2/5 = ?/10 = 0.4
2*(2/5) = (2*2)/(2*5) = 4/10
? = 4

8 0

4 years ago