All categories

2 years ago

I will mark brainliest when it lets me please help me if you can x2 – 9 = 91

Mathematics

1 answer:

jok3333 [9.3K]2 years ago

3 0

Answer:

x=10,−10

Step-by-step explanation:

one of those two

You might be interested in

Your basketball team plays 5 games, your team scores 10 points in the first game, 3 points im the second game, 2 points in the t

andrew-mc [135]

I believe the answer is 4 points. Hope this helps!

4 0

3 years ago

jenna's rectangular garden borders a wall. she buys 80 ft of fencing. what are the dimensions of the garden that will maximize i

FrozenT [24]

Answer:

The dimensions are x =20 and y=20 of the garden that will maximize its area is 400

Step-by-step explanation:

Step 1:-

let 'x' be the length and the 'y' be the width of the rectangle

given Jenna's buys 80ft of fencing of rectangle so the perimeter of the rectangle is 2(x +y) = 80

x + y =40

y = 40 -x

now the area of the rectangle A = length X width

A = x y

substitute 'y' value in above A = x (40 - x)

A = 40 x - x^2 .....(1)

Step :2

now differentiating equation (1) with respective to 'x'

$\frac{dA}{dx} = 40 -2x$ ........(2)

Find the dimensions

$\frac{dA}{dx} = 0$

40 - 2x =0

40 = 2x

x = 20

and y = 40 - x = 40 -20 =20

The dimensions are x =20 and y=20

length = 20 and breadth = 20

Step 3:-

we have to find maximum area

Again differentiating equation (2) with respective to 'x' we get

$\frac{d^2A}{dx^2} = -2$

Now the maximum area A = x y at x =20 and y=20

A = 20 X 20 = 400

Conclusion:-

The dimensions are x =20 and y=20 of the garden that will maximize its area is 400

verification:-

The perimeter = 2(x +y) =80

2(20 +20) =80

2(40) =80

80 =80

8 0

3 years ago

You and your friend caught 36 sunfish in lake Okeechobee the number y of sunfish by your friend is 8 more than the number x caug

kotykmax [81]

8x+x=36
9×=36
x=4
why 20 characters

4 0

3 years ago

Determine the general solution of: sin 3x - sin x = cos2x

SpyIntel [72]

Sin³ x-sin x=cos ² x

we know that:
sin²x + cos²x=1 ⇒cos²x=1-sin²x
Therefore:

sin³x-sin x=1-sin²x
sin³x+sin²x-sin x-1=0

sin³x=z

z³+z²-z-1=0

we divide by Ruffini method:
1   1 -1 -1
1 1 2 1 z=1
-------------------------------------
1   2 1 0
-1   -1 -1 z=-1
--------------------------------------
1 1 0 z=-1

Therefore; the solutions are z=-1 and z=1

The solutions are:
if z=-1, then
sin x=-1   ⇒x= arcsin -1=π+2kπ (180º+360ºK) K∈Z

if z=1, then
sin x=1   ⇒ x=arcsin 1=π/2 + 2kπ (90º+360ºK) k∈Z

π/2 + 2kπ U   π+2Kπ=π/2+kπ k∈Z ≈(90º+180ºK)

Answer: π/2 + Kπ or 90º+180ºK K∈Z
Z=...-3,-2,-1,0,1,2,3,4....

6 0

3 years ago

Why is 1 + (−5) equal to −4? PLEASE HELP

AfilCa [17]

Answer:

Since the -5 is a bigger number than 1 you would keep the negative and carry it to the -4.

Step-by-step explanation:

7 0

3 years ago