Answer:
1.Second equation
2.First equation
3.4
4. is the
Step-by-step explanation:
We are given that two system of equations
System A:
(Equation I )
( Equation II)
And solution (5,2)
System B:
(Equation I)
( equation II)
We have to fill correct value in the blank space
Equation one of system A is multiplied by 4 then we get
(Equation III)
Adding second equation of system A and equation III
Then we get 
Solving equations of system B
We get x=
Substitute x= 5 in equation I of system B then we get


Hence, the solution of system B is (5,2).
Hence, to get system B , the second equation in system A is replaced by the sum of that equation and equation I is multiplied by 4 .The solution to system B is the same as the solution of system A.