All categories

3 years ago

What is. -3 - 9n= 42

Mathematics

2 answers:

dlinn [17]3 years ago

7 0

$-3 - 9n= 42 \\\\
-9n=45\\\\
n=-5$

BartSMP [9]3 years ago

4 0

N = -5

-3 + (-9n) = 42
- -3 - -3

-9n = 45
/-9 /-9

n = -5

You might be interested in

I feed to find the circumference

fgiga [73]

answer:

131.88 inches

step-by-step explanation:

know the formula: 2πr
now plug in what we have

2πr = circumference

2(21)(3.14)

= 131.88

6 0

3 years ago

Find all roots: x^3 + 7x^2 + 12x = 0 Show all work and check your answer.

Aliun [14]

The three roots of x^3 + 7x^2 + 12x = 0 is 0,-3 and -4

Solution:

We have been given a cubic polynomial.

$x^{3}+7 x^{2}+12 x=0$

We need to find the three roots of the given polynomial.

Since it is a cubic polynomial, we can start by taking ‘x’ common from the equation.

This gives us:

$x^{3}+7 x^{2}+12 x=0$

$x\left(x^{2}+7 x+12\right)=0$ ----- eqn 1

So, from the above eq1 we can find the first root of the polynomial, which will be:

x = 0

Now, we need to find the remaining two roots which are taken from the remaining part of the equation which is:

$x^{2}+7 x+12=0$

we have to use the quadratic equation to solve this polynomial. The quadratic formula is:

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

Now, a = 1, b = 7 and c = 12

By substituting the values of a,b and c in the quadratic equation we get;

$\begin{array}{l}{x=\frac{-7 \pm \sqrt{7^{2}-4 \times 1 \times 12}}{2 \times 1}} \\\\{x=\frac{-7 \pm \sqrt{1}}{2}}\end{array}$

Therefore, the two roots are:

$\begin{array}{l}{x=\frac{-7+\sqrt{1}}{2}=\frac{-7+1}{2}=\frac{-6}{2}} \\\\ {x=-3}\end{array}$

And,

$\begin{array}{c}{x=\frac{-7-\sqrt{1}}{2}} \\\\ {x=-4}\end{array}$

Hence, the three roots of the given cubic polynomial is 0, -3 and -4

4 0

3 years ago

Can you please help me with this one

My name is Ann [436]

Answer:

6x=-60

Step-by-step explanation:

3 0

3 years ago

Your 3 nieces and 3 nephews (6 children total) are visiting for the holidays. You must give them each a present. They all love l

marusya05 [52]

Answer:

The 6 Lego kits can be selected from the 9 available Lego kits in 84 ways.

Step-by-step explanation:

Use combinations to solve this problem.

Combination is defined as the selection of r elements from n distinct objects irrespective of the order. The objects cannot be replaced.

There are 9 Lego kits available.

And the total number of children is 6.

That is, we need to select 6 Lego kits from the 9 available Lego kits.

6 Lego kits can be selected from the 9 available Lego kits in $9\choose 6$ ways.

Solving the combination as follows:

${9\choose 6}=\frac{9!}{6!\times(9-6)!} \\=\frac{362880}{720\times6}\\ =84$

Thus, there are 84 ways to select 6 Lego kits from 9 available Lego kits.

4 0

3 years ago

Pleaseee helllpp meee

PIT_PIT [208]

The answer is y = 0.5 x

6 0

3 years ago

Read 2 more answers