Respuesta :
Answer:
Step-by-step explanation:
AI-generated answer
To find the positive solution for this problem, we can set up an equation based on the given information.
Let's say the number we are looking for is represented by "x".
The problem states that 7 times a number is 8 less than the square of that number. In equation form, this can be written as:
7x = x^2 - 8
To solve this equation, we can rearrange it to form a quadratic equation:
x^2 - 7x - 8 = 0
Next, we can factor the quadratic equation:
(x - 8)(x + 1) = 0
Setting each factor equal to zero gives us two possible solutions:
x - 8 = 0 or x + 1 = 0
Solving for x in each equation gives us:
x = 8 or x = -1
Since we are looking for the positive solution, we can conclude that the positive solution for the equation 7x = x^2 - 8 is x = 8.
Therefore, the positive solution for the given problem is x = 8.
Answer:
5.56 (Nearest 3s.f.)
Step-by-step explanation:
Let that unknown number be n
7 x n = n^2 - 8 (7n is smaller than n^2 by 8)
Create Quadratic Equation:
n^2 -7n +8 =0
Most students struggle after this because this equation cannot be factorized like this (x+...)(x-...) because the ans won't be a whole number.
This is where we use the formula (in the picture below)
If you're doing this sort of qn, your teacher should have alr taught you how to use this formula but no matter, quad formulas usually come in this format:
ax^2+bx+c (plus signs can be minus, doesn't matter)
In this case,
a= 1
b= -7
c= 8
Plop them into the formula (in the pic above)
They only want the positive answer, so 5.56 (3s.f.)
You can double check by working backwards.
