Answer:
Step-by-step explanation:
2)
y = x - 4
y = -x + 2
as they are equal:
-x + 2 = x - 4
-x - x = -4 - 2
-2x = -6
x = 3
y = -x + 2
y = -3 + 2
y = -1
solutions: (3,-1)
3)
y = 3x + 1
y = 5x - 3
as y are equal:
5x - 3 = 3x + 1
5x - 3x = 1 + 3
2x = 4
x = 2
y = 3x + 1
y = 3(2) + 1
y = 6 + 1
y = 7
solutions: (2,7)
4)
2x + y = 8
y = x - 7
insert equation x - 7 in replace of y in equation 1
2x + x - 7 = 8
3x - 7 = 8
3x = 15
x = 5
y = x - 7
y = 5 - 7
y = -2
solution's: (5,-2)