Question

Five times of a positive whole number is 3 less than twice the square of the number.the number is

Answer 1

Let the number be x,

5 times of x =  5x

3 less than twice of square of x = 2x² - 3 

In question,

→ 5x = 2x²- 3 

→ 2x² - 5x - 3 = 0

→ 2x² - (6 - 1)x -3 = 0

→ 2x² - 6x + x - 3 = 0 

→ 2x(x -3) +1(x-3) = 0 

→ (x -3) (2x +1) = 0 

x = 3 or x = (-1/2)

x can't be negative  (Given in the Question), so number is 3 

Answer 2

Answer:

Let the number be x,

5 times of x =  5x

3 less than twice of square of x = 2x² - 3  

Step-by-step explanation:

In question,

→ 5x = 2x²- 3  

→ 2x² - 5x - 3 = 0

→ 2x² - (6 - 1)x -3 = 0

→ 2x² - 6x + x - 3 = 0  

→ 2x(x -3) +1(x-3) = 0  

→ (x -3) (2x +1) = 0  

x = 3 or x = (-1/2)

x can't be negative  (Given in the Question), so number is 3