B
Step-by-step explanation:
Given
y = x² - 10x + 9
Using the method of completing the square
add/subtract (half the coefficient of the x- term)² to x² - 10x
y = x² + 2(- 5)x + (- 5)² - (- 5)² + 9
= (x - 5)² - 25 + 9
= (x - 5)² - 16 → B
42.4
step-by-step explanation:
convert to decimal
eve and marks ratios are equivalent