49.
and
50.
and
Explanation:
We are going to solve these systems of equations using the elimination method.
49. Given:
(1)
(2)
Multiply Eqn(1) by 7 and multiply Eqn(2) by -4 to get
Adding the two equations above, we get
Substituting this value for a into Eqn(2), we get
50. Given:
(3)
(4)
Multiplying Eqn(3) by -5, we get
Adding the two equations above, we get
Plugging in the value of x into Eqn(3), we get the value for y as
or