Answer:
B.) 18
Step-by-step explanation:
To find the correct b value we use this formula
b² - 4ac = 0
b = What we are solving for
a = 1
c = 81
b² - 4(1)(81) = 0
b² - 324 = 0
b² = 324

b = ±18
And 18 is one of the answer choices
So B.) 18 is the correct answer.
Answer:
150 steps
Step-by-step explanation:
GOING UP:
Steps taken per second = speed = 3steps/s
Let Time taken = y
Number of steps = steps taken per second × time taken
Number of steps = 3 × y - - - - (1)
COMING DOWN:
Steps taken per second = 2steps/s
Total time taken = y + 25
Number of steps = 2 × (y + 25)
Number of steps = 2y + 50 - - - - - (2)
Equating (1) and (2)
3y = 2y + 50
3y - 2y = 50
y = 50
Substitute y = 50 into either (1) or (2)
Put y= 50 into (1)
Number of steps = 3y
Number of steps = 3(50)
Number of steps = 150