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

J = 5 and k = - 2 that is your answer