QUICK HELP?
Solve the following system of equations by linear combination:

2d – e = 7
d + e = 5

There is no solution.
There are an infinite number of solutions.
The solution is (3, –1).
The solution is (4, 1).

Question

QUICK HELP?
Solve the following system of equations by linear combination:

2d – e = 7
d + e = 5

       There is no solution.
       There are an infinite number of solutions.
       The solution is (3, –1).
       The solution is (4, 1).

amoodarya · Answer

add them 
adding the equation is a linear combination

amoodarya · Answer

by adding  you will have 
2d-e+d+e=7+5
3d=12
d=4
now put d in one of them 
2d-e=7
8-e=7
e=1
(d,e)=(4,1)