The sum of a whole number and twice the square of the number is 10. Find the number

Hey there !

Solution:

Let the number be x

=> x + 2x² = 10

=> 2x² + x - 10 = 0

Factorising the quadratic equation we get,

=> 2x² + 5x - 4x - 10 = 0

=> x ( 2x + 5 ) -2 ( 2x + 5 ) = 0

=> ( x - 2 ) ( 2x + 5 ) = 0

=> x = 2, -5/2

Since x is a whole number, -5 / 2 wont be applicable.

Hence x = 2.

Hence the number is 2.

Hope my answer helped !

Step-by-step explanation:

if you explain the the question more correctly i might be able to answer this better

step-by-step explanation: