Question

Write and solve a system of equations for the situation below. Be sure to define your variables, show all your steps, and interpret your solution. (8 points) Lily is a cross country skier. On Friday and Saturday, she skied a total of 63 miles. On Friday, she skied twice as many miles as she did on Saturday. How far did she ski on each day?

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Answer 1

She ski 21 miles on Saturday and 42 miles on Friday

Explanation:

Come on, she skated 63 miles on the two days, and on Friday I skated twice on Saturday, so let's assume that Friday is x and Saturday y

Then

`x = 2y \\ x + y = 63 \\ 2y + y = 63 \\ y = 21 \\ x = 42`

Answer 2

friday: 42 miles

saturday: 21 miles

Explanation:

f = distance skied on friday

s = distance skied on saturday

So the equations are:

f + s = 63

f = 2s

to solve them, fill in the second in the first:

2s + s = 63

3s = 63

s = 63/3 = 21

f = 2*21 = 42