All categories

3 years ago

X^2−4x−21 I need help with this question and please right every step of it

Mathematics

2 answers:

Damm [24]3 years ago

3 0

Answer:

<h3> $\boxed{ \boxed{ \sf{ \bold{( x - 7)(x + 3)}}}}$ </h3>

Step-by-step explanation:

$\sf{ {x}^{2} - 4x - 21}$

Here, we have to find the two numbers that subtracts to 4 and multiplies to 21

⇒ $\sf{ {x}^{2} - (7 - 3)x - 21}$

⇒ $\sf{ {x}^{2} - 7x + 3x - 21}$

Factor out X from the expression

⇒ $\sf{ x(x - 7) + 3x - 21}$

Factor out 3 from the expression

⇒ $\sf{x(x - 7) + 3(x - 7)}$

Factor out x-7 from the expression

⇒ $\sf{(x - 7)(x + 3)}$

Hope I helped!

Best regards!!

kari74 [83]3 years ago

3 0

Answer:

$\boxed{\boxed{\bold{(x - 7)(x + 3)}}}$

Step-by-step explanation:

${x}^{2} - 4x - 21 \\ {x}^{2} - 7x + 3x - 21 \\ x(x - 7) + 3(x - 7) \\ (x - 7)(x + 3)$

You might be interested in

What is the surface area of the same prism?

vladimir2022 [97]

I’m confused there are no numbers ?

5 0

3 years ago

If two events A and B are independent, and you know that P(A) =

boyakko [2]

Answer:

i think its 7/10

Step-by-step explanation:

4 0

3 years ago

Find the missing length!!!!!

sineoko [7]

Answer:

2x^2+4x

HOPE THIS HELPS

-Todo <3

Step-by-step explanation:

9x^2+2x

2x^2+4x

(if you would like an explanation let me know :D)

3 0

3 years ago

How do you solve this equation 4-2(v-6)=-8

Umnica [9.8K]

Answer:

first, subtract 4 from each side of the equation to isolate the term with parenthesis while keeping the equation balanced:

−4+4−2(v−6)=−4−8

0−2(v−6)=−12

−2(v−6)=−12

Next, divide each side of the equation by −2 to eliminate the need for parenthesis while keeping the equation balanced:

−2(v−6)−2=−12−2

−2

(v−6)−2

v−6=6

Then, add 6 to each side of the equation to solve for v term while keeping the equation balanced:

v−6+6=6+6

v−0=12

v=12

3 0

3 years ago

Read 2 more answers

Find area of the shaded region.

Monica [59]

Answer:

The area of the shaded region is about 38.1 square centimeters.

Step-by-step explanation:

We want to find the area of the shaded region.

To do so, we can first find the area of the sector and then subtract the area of the triangle from the sector.

The given circle has a radius of 6 cm.

And the given sector has a central angle of 150°.

The area for a sector is given by the formula:

$\displaystyle A=\pi r^2\cdot \frac{\theta}{360^\circ}$

In this case, r = 6 and θ = 150°. Hence, the area of the sector is:

$\displaystyle \begin{aligned}A&=\pi(6)^2\cdot \frac{150}{360}\\ &=36\pi\cdot \frac{5}{12}\\&=3\pi \cdot 5\\&=15\pi \text{ cm}^2\end{aligned}$

Now, we can find the area of the triangle. We can use an alternative formula:

$\displaystyle A=\frac{1}{2}ab\sin(C)$

Where a and b are the side lengths, and C is the angle between them.

Both side lengths of the triangle are the radii of the circle. So, both side lengths are 6.

And the angle C is 150°. Hence, the area of the triangle is:

$\displaystyle A=\frac{1}{2}(6)(6)\sin(150)=18\sin(150)$

The area of the shaded region is equivalent to the sector minus the triangle:

$A_{\text{shaded}}=A_{\text{sector}}-A_{\text{triangle}}$

Therefore:

$A_{\text{shaded}}=15\pi -18\sin(150)$

Use a calculator:

$A_{\text{shaded}}=38.1238...\approx 38.1\text{ cm}^2$

The area of the shaded region is about 38.1 square centimeters.

6 0

3 years ago