Answer:
(x - 2)² - 30
Step-by-step explanation:
To complete the square
add/subtract ( half the coefficient of the x- term )² to x² - 4x
f(x) = x² + 2(- 2)x + 4 - 4 - 26 = (x - 2)² - 30
The answer is 12,825 kg because if one car equals 1425 kg and a car carrier can hold 9 cars, then you just have to multiply 1425 by 9 to get 12,825
Based on the calculations, the unknown number is equal to 
- Let the unknown number be x.
<h3>How to find an
unknown number:</h3>
Translate the word problem into an algebraic expression, we have;
Adding 21 to the unknown number:

Multiplying the result by 3:

84 more than two-thirds of the unknown number:

Equating the equations, we have:

Cross-multiplying, we have:

Read more on word problems here: brainly.com/question/13170908
28 = k - 12
28 + 12 = k
40 = k