Solve, using the substitution method.
j + k = 3
j – k = 7

To use the substitution method, you first need to set j or k = to something else like this. j+k=3   subtract k from both sides to get j=3-k

Now use the second equation and substitute 3-k where j is like this.  3-k-k=7

3-2k=7 subtract 3 from both sides to get -2k=4

divide both sides by -2 to get k=-2

now use -2 for k and solve for j in either equation and you will get. j=5

1 mph

step-by-step explanation:

if the question is asking how much does she drive per mile then,

13 / 13 = 1 mph