Question

Three more than a positive number is twenty less than its square. What is the number?

Answer 1

Answer:

the +ve no. = 2

Step-by-step explanation:

let the number be x - 3

three more than a positive number = x

acc. to condition

$x^{2}$ - 20 =  x

$x^{2} - x - 20 = 0$

$x^{2} - 5x + 4x - 20 = 0$

$x(x - 5) +4(x - 5) = 0$

$(x+4)(x-5) = 0$

Case 1

$x + 4 = 0$

$x = -4$

the Number cannot be negative because the condition given in question

Case 2

$x - 5 = 0$

$x = 5$

Hence, the positive number

$= x - 3$

$= 5 - 3$

$= 2$