Respuesta :
3 times a number is 4 less than the square of that number. The negative solution is -1
What are quadratic equations?
Quadratic equations are of the form ax² + bx + c where a ≠ 0.
What is factorization?
Factorization, often known as factoring, is the process of expressing a number or another mathematical object or mathematical equations as a product of several factors.
Now, In the given question let's first assume that the unknown number is a variable x.
So, 3 times that number is (3 × x)
And then, 4 less than the square of that number is (x² - 4)
Now, as the question states that 3 times a number is 4 less than the square of that number,
So we can write,
3x = x² - 4
Now, we have to solve this quadratic equation with the help of factorization.
To solve the quadratic equation we first bring all the terms to any of the sides and after rearranging a little the equation is as follows:
x² - 3x - 4 = 0
Now, if we want to find the factors in the form ax² + bx + c we need to multiply a and c and then we have to identify what two numbers sum up to b and multiply to ac.
Here, a = 1, b = -3 and c = -4
Now, ac = -4
So, we have to identify what two numbers sum up to b and multiply to ac. The numbers are -4 and 1 and we can check that they sum up to -3 and multiply to -4.
So first we have to split the equation: x² - 3x - 4 = 0
x² - 4x + 1x - 4 = 0
Now, we have to group the above equation,
(x² - 4x) + (1x - 4) = 0
Taking x common from the first group and taking 1 common from the second group we get,
(x)(x - 4) + (1)(x - 4) = 0
Now, again taking (x - 4) common from the equation we get,
(x - 4) × (x + 1) = 0
So, we set each factor to zero now,
(x - 4) = 0
Adding 4 to each side of the equation we get,
x - 4 + 4 = 4
Simplifying we get,
x = 4
(x + 1) = 0
Adding -1 to each side of the equation we get,
x + 1 - 1 = -1
Simplifying we get,
x = -1
So, we now have two solutions of x that is 4 and -1
But according to the question we only need the negative one.
Therefore, the negative solution is -1
To know more about how to solve quadratic equations by factorization
use this - brainly.com/question/544930
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