Question

5 times of a positive whole number is 3 less than twice the square of the number find the number

Answer 1

Answer :

Suppose that positive whole number is x,

So according to the question,

5(x) + 3 = 2(x)^2 ---------(1)

=> 5x + 3 = 2x^2

=> 2x^2 - 5x - 3 = 0

=> 2x^2 - 6x + x - 3 = 0

=> 2x(x - 3) + 1(x - 3)

=> (x - 3) (2x + 1) = 0

=> x = 3 Or x = -1/2

Since according to the question, x is the positive whole number,

=> x = 3


● Lets verify our answer and put value of x as 3 in the equation (1),

5(x) + 3 = 2x^2
Lets put x = 3 in LHS and RHS

=> LHS = 5×3 + 3 = 18
=> RHS = 2×(3)^2 = 2×9 = 18
Hence LHS = RHS

●So the required positive whole number is 3


●●● Hope It Helps ●●●