Answer:
There is one unique solution, (−6, 5).
Explanation:
2x + 4y = 8
2x + 6y = 18
2x + 4y = 8 ==> solve for 2x
2x + 4y - 4y = 8 - 4y
2x = 8 - 4y
2x + 6y = 18 ==> solve for 2x
2x + 6y - 6y = 18 - 6y
2x = 18 - 6y
8 - 4y = 18 - 6y ==> 2x = 8 - 4y and 2x = 18 - 6y
8 - 4y + 6y = 18 - 6y + 6y ==> solve for y by first adding 6y on both sides to
remove negative y
8 + 2y = 18 ==> simplify
8 - 8 + 2y = 18 - 8 ==> isolate y
2y = 10
y = 5
2x + 4(5) = 8 ==> substitute 5 for y in 2x + 4y = 8
2x + 20 = 8
2x - 20 + 20 = 8 - 20 ==> subtract 20 on both sides to isolate 2x
2x = -12
x = -6
x = -6, y = 5 ==> (6, 5)
Answer: There is one unique solution, (−6, 5).