Answer:
A = 33.33
Step-by-step explanation:
P = 0.006A^2 - 0.02A + 120
*** P = 126 ***
126 = 0.006A^2 - 0.02A + 120
126 = (3/500)A^2 - (1/50)A + 120
*** multiplied with 500 on both sides ***
63000 = 3A^2 - 10A + 60000
63000 - 3A^2 + 10A - 60000 = 0
3000 - 3A^2 + 10A = 0
3A^2 - 10A - 3000 = 0
3A^2 + 90A - 100A - 3000 = 0
3A(A + 30) - 100(A + 30) = 0
(A + 30)(3A - 100) = 0
A + 30 = 0 | 3A - 100 = 0
A = -30 | 3A = 100
A = -30 | A = 100/3
Human age cannot be negative so
A = 100/3 = 33.33