(ii) 3x + 4y + 5 = 0; y = x + 4
3x + 4y = - 5
X
|
- 3
|
5
|
1
|
Y
|
1
|
-5
|
-2
|
(X,Y)
|
(-3,1)
|
(5,-5)
|
(1,-2)
|
Put x = - 3
∴ 3(-3) + 4y = - 5
∴ -9 + 4y = - 5
∴ 4y = -5 + 9
∴ 4y = 4
∴ y = 4/4
∴ y = 1
|
Put x = 5
∴ 3(5) + 4y = - 5
∴ 15 + 4y = - 5
∴ 4y = - 5 – 15
∴ 4y = - 20
∴ y = -20/4
∴ y = - 5
|
Put x = 1
∴ 3(1) + 4y = - 5
∴ 3 + 4y = - 5
∴ 4y = - 5 – 3
∴ 4y = - 8
∴ y = -8/4
∴ y = - 2
|
y = x + 4
X
|
0
|
1
|
2
|
Y
|
4
|
5
|
6
|
(X,Y)
|
(0,4)
|
(1,5)
|
(2,6)
|
Put x = 0
∴ y = 0 + 4
∴ y = 4
|
Put x = 1
∴ y = 1 + 4
∴ y = 5
|
Put x = 2
∴ y = 2 + 4
∴ y = 6
|
x = - 3 and y = 1 is the solution of given simultaneous equations.
