Question

1. Solve, using the substitution method.

m + n = 5
m – n = 3

There is no solution.
The solution is (2, –1)
The solution is (4, 1)
There are an infinite number of solutions.

Answer 1

m + n = 5 ---> m = 5 - n
now sub 5 - n in for m in the other equation
m - n = 3
(5 - n) - n = 3
5 - 2n = 3
-2n = 3 - 5
-2n = -2
n = 1

now sub 1 in for n into either of the original equations
m + n = 5
m + 1 = 5
m = 5 - 1
m = 4

The solution is (4,1)

Answer 2

thx a million man :D