All categories

3 years ago

20% of Aussies have blue

Mathematics

1 answer:

notsponge [240]3 years ago

6 0

Answer:

Step-by-step explanation:

Step 1: 4 = 20% × Y

Step 2: 4 = 20/100 × Y

Multiplying both sides by 100 and dividing both sides of the equation by 20 we will arrive at:

Step 3: Y = 4 × 100/20

Step 4:Y = 4 × 100 ÷ 20

Step 5: Y = 20

You might be interested in

the football team gained 7 yards. gained 4 yards, lost 5 yards, gained 21 yards, lost 2 yards and gained 4yards to their 43 yard

svet-max [94.6K]

7+4-5+21-2+4=29 Then I used football knowledge to find that they started on the other teams 28 yard line :)

3 0

3 years ago

Which of the given points would be in a table generated by the equation below?

bixtya [17]

D is the answer. Putting this because it has to be 20 characters

7 0

3 years ago

Find the dimensions of the open rectangular box of maximum volume that can be made from a sheet of cardboard 21 in. by 12 in. by

a_sh-v [17]

Answer:

Dimension of the box is $16.1\times 7.1\times 2.45$

The volume of the box is 280.05 in³.

Step-by-step explanation:

Given : The open rectangular box of maximum volume that can be made from a sheet of cardboard 21 in. by 12 in. by cutting congruent squares from the corners and folding up the sides.

To find : The dimensions and the volume of the box?

Solution :

Let h be the height of the box which is the side length of a corner square.

According to question,

A sheet of cardboard 21 in. by 12 in. by cutting congruent squares from the corners and folding up the sides.

The length of the box is $L=21-2h$

The width of the box is $W=12-2h$

The volume of the box is $V=L\times W\times H$

$V=(21-2h)\times (12-2h)\times h$

$V=(21-2h)\times (12h-2h^2)$

$V=252h-42h^2-24h^2+4h^3$

$V=4h^3-66h^2+252h$

To maximize the volume we find derivative of volume and put it to zero.

$V'=12h^2-132h+252$

$0=12h^2-132h+252$

Solving by quadratic formula,

$h=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

$h=\frac{-(-132)\pm\sqrt{132^2-4(12)(252)}}{2(12)}$

$h=\frac{132\pm72.99}{24}$

$h=2.45,8.54$

Now, substitute the value of h in the volume,

$V=4h^3-66h^2+252h$

When, h=2.45

$V=4(2.45)^3-66(2.45)^2+252(2.45)$

$V\approx 280.05$

When, h=8.54

$V=4(8.54)^3-66(8.54)^2+252(8.54)$

$V\approx -170.06$

Rejecting the negative volume as it is not possible.

Therefore, The volume of the box is 280.05 in³.

The dimension of the box is

The height of the box is h=2.45

The length of the box is $L=21-2(2.45)=16.1$

The width of the box is $W=12-2(2.45)=7.1$

So, Dimension of the box is $16.1\times 7.1\times 2.45$

6 0

3 years ago

oy is training for a triathlon. She runs a distance of 2x miles, cycles a distance of (x2 + 7) miles, and swims a distance of (x

Evgesh-ka [11]

Add
2x+x²+7+x-2
x²+3x+5 is the distance

7 0

3 years ago

Find the value of the missing coefficient in the factored form of 8f^3-216g^3

adoni [48]

Answer:

The value of the missing coefficient is 12

Step-by-step explanation:

* Lets explain how to factorize the difference of two cubes

- The factorization of the difference of two cubes like a³ - b³, is a

product of a binomial and trinomial

- The binomial is the cube root of the first term and the second term

∵ The ∛a³ = a and ∛b³ = b

∴ The binomial is (a - b)

- We will find the trinomial from the binomial by square the 1st term

of the binomial and multiply the 1st term and the 2nd term of the

binomial with opposite sign of the binomial and square the 2nd

term of the binomial

∴ The trinomial is (a² + ab + b²

∴ The factorization of (a³ - b³) is (a - b)(a² + ab + b²)

* Lets solve the problem

∵ 8f³ - 216g³ is the difference of two cubes

∵ ∛(8f³) = 2f

∵ ∛(216g³) = 6g

∴ The binomial is (2f - 6g)

- Lets make the trinomial

∵ (2f)² = 4f²

∵ (2f)(6g) = 12fg

∵ (6g)² = 36g²

∴ The trinomial = (4f² + 12fg + 36g²)

∴ The factorization of 8f³ - 216g³ = (2f - 6g)(4f² + 12fg + 36g²)

∴ The value of the missing coefficient is 12

7 0

3 years ago