Julia ran and bikes for a total of 40 miles in 5.8 hours. Her average running speed was 5.5 mph. Her average biking speed was 13.5 mph.
Let x = total hours Julia ran
Ley y = total hours Julia biked
Use substitution to solve for x and y.SHOW ALL WORK.Round answers to nearest tenth.
We have that
x + y = 5.8 ⇒ y = 5.8 - x (1)
And note that rate * time = distance covered.....so..
5.5x + 13.5y = 40 (2) put (1) into (2) for y and we have
5.5x + 13.5(5.8 - x) = 40 simplify
5.5x + 78.3 - 13.5 x = 40
-8x + 78.3 = 40 subtract 78.3 from both sides
-8x = - 38.3 divide both sides by -8
x ≈ 4.8 hrs running
And y ≈ 5.8 - x = 5.8 - 4.8 ≈ 1 hrs biking