Question

four times the square of a number is 45 more than eight times the number. what is the number​

Answer 1

Answer:

x = 9/2

Step-by-step explanation:

let x be unknown

4(x^2) = 45 + 8x

4x^2 - 8x - 45 = 0

(2x - 9) (2x + 9) = 0

x = 9/2

x = -5/2

Consider the positive value

x = 9/2

Answer 2

GivEn :-

• Four times the square of a number is 45 more than eight times the number .

To FinD :-

• To find the number

CalculatioN :-

Let us consider the number to be x and solve the question .

→ Fourtimes the square of x = 4x^2

→ Then,the number is 45 more than Eight times the number .

• 4( x^2 ) = 45 + 8x

• 4x^2 - 8x +45 = 0

Simplification of the quadratic equation by spliting the middle term.

• (2x - 9) ( 2x + 5 ) = 0

Hence x can be two possibilities.

Either,

• x = 9/2

• x = -5/2

Negative number is not possible so we get x as

$\boxed{ \bold{ \red{Hence \: 'x' = \frac{9}{2} }{} }{} }{}$