If the number is x, then:
6x+1= (x-1)^2
Now we just need to simplify it
6x+1=(x-1)*(x-1)
6x+1=x^2-2x+1
8x=x^2
8=x
The number is 8.
To check the answer
6*8+1=7^2
49=49
correct :)
Let sum of 3 numbers be x.
Average of 3 numbers and 8 =

25 =

100 = x +8
x= 92.
The sum of 3 numbers is 92.
Let the given complex number
z = x + ix = 
We have to find the standard form of complex number.
Solution:
∴ x + iy = 
Rationalising numerator part of complex number, we get
x + iy = 
⇒ x + iy = 
Using the algebraic identity:
(a + b)(a - b) =
- 
⇒ x + iy = 
⇒ x + iy =
[ ∵
]
⇒ x + iy =
⇒ x + iy =
⇒ x + iy =
⇒ x + iy = 1 - i
Thus, the given complex number in standard form as "1 - i".
They're all used for differentiating types of measurement in mathematics and science.