Unsure on how to solve this math problem

Question

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:gives a person's blood pressure, , at age years.

A.) Find the systolic pressure, to the nearest tenth of a millimeter, for a person of age 48 years.

B.) If a person's systolic pressure is 130.58 mm Hg, what is their age (rounded to the nearest whole year)?

Answer 1

A). Plug in 48 for y and use your calculator to find out what P is!

B) Plug 130.58 in for P, then subtract 130.58 from each side, and combine 120- 130.58 on the right. Now you have a quadratic= 0, which you can solve with the quadratic formula-- (you only want the positive answer!), or, better yet substitute x for y, so you have a quadratic in the variable x, and enter y = that quadratic in the variable x and see where the parabola crosses the positive x axis. That's your answer, and round it to a whole number!

Good luck!