Completing the square is a process to find the solutions, or the x-values, to a quadratic equation. This method can only work if it is in the format: x^2 + bx = c
In this equation, the b value is -12 and the c value is -6. The process for completing the square goes like this:
x^2 + bx + (b/2)^2 = c + (b/2)^2
Now let’s solve the equation above using this method.
Step 1: x^2 - 12x + (-12/2)^2 = -6 + (-12/2)^2
Step 2: x^2 - 12x + (-6)^2 = -6 + (-6)^2
Step 3: x^2 - 12x + 36 = -6 + 36
Step 4: x^2 - 12x + 36 = 30
Now, to factor it. After doing the process until now, the left side of the equation can ALWAYS be in the format: (x + a)^2
Step 5: x^2 - 12x + 36 can be factored in this format as (x - 6)^2
Step 6: (x - 6)^2 = 30
Step 7: x - 6 = √30
Step 8: x = 6 ±√30
I believe it is D. Hope this helps!
4^4 * 4^(-9) = 4^(4-9) = 4^(-5) or 1/(4^5)
<span>Simplifying
x + -1.4 = 7.82
Reorder the terms:
-1.4 + x = 7.82
Solving
-1.4 + x = 7.82
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '1.4' to each side of the equation.
-1.4 + 1.4 + x = 7.82 + 1.4
Combine like terms: -1.4 + 1.4 = 0.0
0.0 + x = 7.82 + 1.4
x = 7.82 + 1.4
Combine like terms: 7.82 + 1.4 = 9.22
x = 9.22
Simplifying
x = 9.22</span>
Yes it is correct because you would multiply 30 by 7 which equals 210 + the extra 20 dollars / 50 dollars (idk).. she will have more than enough though