a formula for normal systolic blood pressure for a man age A, measured in mmHg, is given as P= 0.006A^2-0.02A+120. Find the age of a man whose normal blood pressure messures126 mmHg.

Respuesta :

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