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3 years ago

There are 20 crayons in a tin 4 crayons are red

Mathematics

1 answer:

irga5000 [103]3 years ago

5 0

The answer is 5 I suppose.

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(3x+2)+(2x^2+3x-1)<br><br> Please answer ty:)

Paul [167]

Answer = 2x^2+6x+1

3x+2+2x^2+3x-1
3x+1+2x^2+3x
Now combine like terms
3x+1+2x^2+3x
6x+1+2x^2
Rearrange terms
6x+1+2x^2
2x^2+6x+1

4 0

2 years ago

A rancher wants to fence in an area of 1500000 square feet in a rectangular field and then divide it in half with a fence down t

VLD [36.1K]

Answer:

6000 ft

Step-by-step explanation:

Let length of rectangular field=x

Breadth of rectangular field=y

Area of rectangular field= $1500000$ square ft

Area of rectangular field= $l\times b$

Area of rectangular field= $x\time y$

$1500000=xy$

$y=\frac{1500000}{x}$

Fencing used ,P(x)= $x+x+y+y+y=2x+3y$

Substitute the value of y

P(x)= $2x+3(\frac{1500000}{x})$

$P(x)=2x+\frac{4500000}{x}$

Differentiate w.r.t x

$P'(x)=2-\frac{4500000}{x^2}$

Using formula: $\frac{dx^n}{dx}=nx^{n-1}$

$P'(x)=0$

$2-\frac{4500000}{x^2}=0$

$\frac{4500000}{x^2}=2$

$x^2=\frac{4500000}{2}=2250000$

$x=\sqrt{2250000}=1500$

It is always positive because length is always positive.

Again differentiate w.r.t x

$P''(x)=\frac{9000000}{x^3}$

Substitute x=1500

$P''(1500)=\frac{9000000}{(1500)^3}>0$

Hence, fencing is minimum at x=1 500

Substitute x=1 500

$y=\frac{1500000}{1500}=1000$

Length of rectangular field=1500 ft

Breadth of rectangular field=1000 ft

Substitute the values

Shortest length of fence used= $2(1500)+3(1000)=6000 ft$

Hence, the shortest length of fence that the rancher can used=6000 ft

3 0

3 years ago

Rationalise the denominator <br>

Margaret [11]

Step-by-step explanation:

1. $\frac{2 \sqrt{3} }{ \sqrt{5} }$

multiply

$\sqrt{5}$

do both the numerator and denominater

$\frac{2 \sqrt{3} }{ \sqrt{5} } \times \frac{ \sqrt{5} }{ \sqrt{5} } = \frac{2 \sqrt{15} }{ \sqrt{25} } = \frac{2 \sqrt{15} }{5}$

8 0

3 years ago

An airplane is preparing to land at an airport. It is 50400 feet above the ground and is descending at the rate of 3000 feet per

Dovator [93]

Answer:

let t = no of minutes when they are at the same altitude

52200 - 3300t = 2500t

52200 = 3300t + 2500t

52200 = 5800t

t = 52200/5800

t = 9 minutes they will be at the same altitude

The altitude:

9*2500 = 22500 ft

Check on other train

52200 - 9(3300) =

52200 - 29700 = 22500 ft

3 0

2 years ago

The cost of coffee is determined by the type of coffee beans that are mixed together. The cost of a local mix of Arabica and Rob

Sati [7]

Substituting 1000 for A, we have 1200R+700,000=1,000,000. Subtracting 700,000 from both sides, we have 1200R=300,000. Dividing by 1200, we see that R=250.

7 0

3 years ago