I believe it is an imaginary number because imaginary numbers are square roots of negative numbers.
Haha, there isn't a thing that makes you 'really smart'.
However, you can grow and improve your knowledge.
The more challenging material you expose yourself to, while putting in the effort to solve them, there's no doubt you'll definitely improve!
+ you can try exercising your brain every now and then by playing trivia games or reading books- do whatever interests you and helps you learn!
Hi there!
Answer:
length = 9 kilometres
Width = 12 kilometres
Let's solve this problem step by step!
To find our answer we need to set up and solve an equation.
Let the length of the rectangle be represented by x.
The width of the rectangle can therefore be expressed by 2x - 6.
The area of a rectangle can be found by using the formula:
A = width × length
Plug in the data from the formula
A = x (2x - 6).
Simplify using rainbow technique.
![x(2x - 6) = 2 {x}^{2} - 6x](https://tex.z-dn.net/?f=x%282x%20-%206%29%20%3D%202%20%7Bx%7D%5E%7B2%7D%20-%206x)
Now we've found the simplified expression that expresses the area of the rectangle. Therefore, we can now set up and start solve the equation.
![2 {x}^{2} - 6x = 108](https://tex.z-dn.net/?f=2%20%7Bx%7D%5E%7B2%7D%20-%206x%20%3D%20108)
Subtract 108
![2 {x}^{2} - 6x - 108 = 0](https://tex.z-dn.net/?f=2%20%7Bx%7D%5E%7B2%7D%20-%206x%20-%20108%20%3D%200)
Divide by 2.
![{x}^{2} - 3x - 54](https://tex.z-dn.net/?f=%20%7Bx%7D%5E%7B2%7D%20-%203x%20-%2054)
![(x - 9)(x + 6) = 0](https://tex.z-dn.net/?f=%28x%20-%209%29%28x%20%2B%206%29%20%3D%200)
Rule AB = 0, gives A is 0 or B is 0.
![x - 9 = 0 \\ x = 9 \\ \\ x + 6 = 0 \\ x = - 6](https://tex.z-dn.net/?f=x%20-%209%20%3D%200%20%5C%5C%20x%20%3D%209%20%5C%5C%20%5C%5C%20x%20%2B%206%20%3D%200%20%5C%5C%20x%20%3D%20-%206)
The length of the rectangle, which was represented by x, must be 9 (since it cannot be a negative number).
Length
![x = 9](https://tex.z-dn.net/?f=x%20%3D%209)
Width
![2x - 6 = 2 \times 9- 6 = 18 - 6 = 12](https://tex.z-dn.net/?f=2x%20-%206%20%3D%202%20%5Ctimes%209-%206%20%3D%2018%20-%206%20%3D%2012)
Answer:
length = 9 kilometres
Width = 12 kilometres
~ Hope this helps you!
Answer:
![x^3+x^2-5x+28](https://tex.z-dn.net/?f=x%5E3%2Bx%5E2-5x%2B28)
Step-by-step explanation:
since a=lw, the area is (x^2-3x+7)(x+4)
1. distribute parentheses ![\left(x^2-3x+7\right)\left(x+4\right)=x^2x+x^2\cdot \:4+\left(-3x\right)x+\left(-3x\right)\cdot \:4+7x+7\cdot \:4](https://tex.z-dn.net/?f=%5Cleft%28x%5E2-3x%2B7%5Cright%29%5Cleft%28x%2B4%5Cright%29%3Dx%5E2x%2Bx%5E2%5Ccdot%20%5C%3A4%2B%5Cleft%28-3x%5Cright%29x%2B%5Cleft%28-3x%5Cright%29%5Ccdot%20%5C%3A4%2B7x%2B7%5Ccdot%20%5C%3A4)
2. apply +(-a)=-a rule ![x^2x+4x^2-3xx-3\cdot \:4x+7x+7\cdot \:4](https://tex.z-dn.net/?f=x%5E2x%2B4x%5E2-3xx-3%5Ccdot%20%5C%3A4x%2B7x%2B7%5Ccdot%20%5C%3A4)
3. Simplify
Steps to simplify:
![x^2x=x^3](https://tex.z-dn.net/?f=x%5E2x%3Dx%5E3)
![3xx=3x^2](https://tex.z-dn.net/?f=3xx%3D3x%5E2)
![3\cdot \:4x=12x](https://tex.z-dn.net/?f=3%5Ccdot%20%5C%3A4x%3D12x)
![7\cdot \:4=28](https://tex.z-dn.net/?f=7%5Ccdot%20%5C%3A4%3D28)
![x^3+4x^2-3x^2-12x+7x+28](https://tex.z-dn.net/?f=x%5E3%2B4x%5E2-3x%5E2-12x%2B7x%2B28)
4. Add like terms ![=x^3+4x^2-3x^2-5x+28](https://tex.z-dn.net/?f=%3Dx%5E3%2B4x%5E2-3x%5E2-5x%2B28)
5. Add like terms ![=x^3+x^2-5x+28](https://tex.z-dn.net/?f=%3Dx%5E3%2Bx%5E2-5x%2B28)
20
Constant in a mathematical expression is a term whose value never changes.
The terms with x and y will vary based on the variable x and or y.