The sum of a number ,its square and its square root is 22 . What is the number ?

1 answer

Let the number be \( x \). According to the problem, we have the equation:

\[ x + x^2 + \sqrt{x} = 22 \]

To solve this equation, we can first rearrange it as:

\[ x^2 + x + \sqrt{x} - 22 = 0 \]

This is a non-linear equation due to the presence of the square root. To make the equation easier to handle, we can substitute \( y = \sqrt{x} \), which means \( x = y^2 \). Substituting this into the equation gives us:

\[ (y^2)^2 + y^2 + y - 22 = 0 \] \[ y^4 + y^2 + y - 22 = 0 \]

Now, we will look for possible rational roots or attempt to find roots using numerical or graphical methods. However, this degree of polynomial could also be complicated; it might help to try specific values for \( y \).

Trying \( y = 2 \):

\[ 2^4 + 2^2 + 2 - 22 = 16 + 4 + 2 - 22 = 0 \]

Thus, \( y = 2 \) is a root. Since \( y = \sqrt{x} \):

\[ \sqrt{x} = 2 \implies x = 2^2 = 4 \]

To confirm, we will substitute \( x = 4 \) back into the original equation:

\[ 4 + 4^2 + \sqrt{4} = 4 + 16 + 2 = 22 \]

The left side equals 22, thus confirming our solution is correct.

Therefore, the number is \( \boxed{4} \).

Similar Questions
    1. answers icon 1 answer
  1. Express in simplest radical form.square root of, 3, x, end square root 3x ​ Answer Multiple Choice Answers square root of, 3,
    1. answers icon 1 answer
  2. Add and Subtract Radicals Quick CheckMath 8 Q2 (Pre-Algebra) / Roots and Irrational Numbers add 2 square root 21 + 3 square root
    1. answers icon 1 answer
  3. Add and Subtract Radicals Quick CheckMath 8 Q2 (Pre-Algebra) / Roots and Irrational Numbers add 3 square root 21 + 7 square root
    1. answers icon 1 answer
more similar questions