18 + 81 = 9(x²<span> + 6x + 9)
</span><span>11 = (x + 3)</span>²
When we are completing the square, we are going to move the value of c across the equals. We will do that by adding, and end up with
18=9(x²+6x)
We take the value of b (the coefficient of x), divide it by 2 and square it:
(6/2)²=3²=9
This is the value that completes the square. However, since the entire square is multiplied by 9, this value must be multiplied by 9 before we can add it across the equals:
18+9(9) = 9(x²+6x+9)
18+81=9(x²+6x+9)
99=9(x²+6x+9)
Dividing both sides by 9, we have:
11=x²+6x+9
11=(x+3)²
Answer:A. provide evidence of a causal relationship between an independent variable and the variable to be forecast
Step-by-step explanation: Casual model tends to show the cause and effect relationship between the dependent variable to be forcasted and the independent variables upon which the dependent variable is dependent.
Casual model is frequently used in the field of Statistics and Economics when making forcasts about future investments or the cause of certain events,knowing what activities to carry out in the future.