SOLUTION: A person's systolic blood pressure, which is measured in millimeters of mercury (mm Hg), depends on a person's age, in years. The equation: P=0.005y2−0.01y+119P=0.005y2-0.01y+

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A person's systolic blood pressure, which is measured in millimeters of mercury (mm Hg), depends on a person's age, in years. The equation: P=0.005y2−0.01y+119P=0.005y2-0.01y+      Log On


   



Question 1140035: A person's systolic blood pressure, which is measured in millimeters of mercury (mm Hg), depends on a person's age, in years. The equation:
P=0.005y2−0.01y+119P=0.005y2-0.01y+119

gives a person's blood pressure,
P
P
, at age
y
y
years.
A.) Find the systolic pressure, to the nearest tenth of a millimeter, for a person of age 40 years.


B.) If a person's systolic pressure is 131 mm Hg, what is their age (rounded to the nearest whole year)?

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
substitute 40 for y
0.005*1600=8
-0.01*40=-0.4
+119
126.6
for the other it is 131=0.005y^2-0.01y+119
or 0.005y^2-0.01y-12=0
multiply by 200to clear decimals
y^2-2y-2400=0
y=(1/2)(2+ sqrt(4+9600))
=50 years old