the square of a number is equal to the sum of 21 and 4 times the number. find the number

WHATS THE EQUATION (AM CONFUSED ?)

so its x=7

x= -3

x^2 = 21 + 4x

ok thanks

You're welcome.

To solve this problem, let's break it down step by step.

1. Assign a variable to represent the unknown number. Let's use "x" for this problem.

2. Translate the given information into an equation. The problem states that "the square of a number is equal to the sum of 21 and 4 times the number." In mathematical terms, this can be expressed as:

x^2 = 21 + 4x

3. Solve the equation to find the value of x. We can rearrange the equation by subtracting 4x from both sides:

x^2 - 4x = 21

4. Now, we have a quadratic equation. To solve it, we can set it equal to zero by subtracting 21 from both sides:

x^2 - 4x - 21 = 0

5. Factor the quadratic equation or use the quadratic formula to solve it. In this case, the equation can be factored as follows:

(x - 7)(x + 3) = 0

This results in two possible solutions: x = 7 or x = -3.

So, the two possible numbers that satisfy the given condition are 7 and -3.