Question

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

number is

a) 3 b) 4 c) –3 d​

Answer 1

Answer:

a) 3

Step-by-step explanation:

Assume that the number is x.

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

As per given condition,

5x = 2x² - 3

→ 5x = 2x² - 3

→ 2x² - 5x - 3 = 0

Split the middle term,

→ 2x² - 6x + x - 3 = 0

→ 2x(x - 3) +1(x - 3) = 0

→ (2x + 1) (x - 3) = 0

On comparing we get,

→ x = -1/3, 3

Negative one neglected.

Hence, the number is 3.