How many solutions does the following set of equations have?

Question

x + y = 3
x +y= -1

A)one
B)none
C)infinite

x+2y=4
x+2y=-2

A)one
B)none
C)infinite

thank you in advance for your help. i am stuck.

Answer 1

y = -x +3
y = -x -1
slope = -1 in both cases and the lines are distinct (different intercepts). Therefore, no solution.

y = -(1/2)x + 2
y = -(1/2)x -1
Ditto

Answer 2

1. zero - these lines are parallel both have slope of -1
2. Same as above - slopes are both -1

good luck!