<u>Method of Elimination:</u>
Given pair of linear equations are:
3x+y = 8 — — —Eqn(i)
On comparing with a₁x+b₁y+c₁ = 0
Where,
5x+y = 10 — ——Eqn(ii)
On comparing with a₂x+b₂y+c2₂ = 0
Where,
- a₂ = 5,
- b₂ = 1, &
- c₂ = -10
a₁/a₂ = 3/5
b₁/b₂ = 1/1= 1
c₁/c₂ = 8/10=4/5
We have,
a₁/a₂ ≠ b₁/b₂ ≠ c₁/c₂
So, Given pair of linear equations in two variables have a unique solution.
Now,
On Subtracting eqn(ii) from eqn(i) then
3x+y = 8
5x+y = 10
(-)
________
-2x+0 = -2
_________
⇛-2x = -2
⇛2x = 2
⇛x = 2/2
⇛x = 1
On Substituting the value of x in eqn(i) then
⇛3(1)+y = 8
⇛3+y = 8
⇛y = 8-3
⇛y = 5
Therefore , The solution = (1,5)
<u>Additional</u><u> comment</u><u>:</u>
- If a₁x+b₁y+c₁ = 0 and a₂x+b₂y+c₂ = 0 are pair of linear equations in two variables then
- If a₁/a₂ ≠b₁/b₂ ≠ c₁/c₂ then they are Consistent and independent lines or Intersecting lines and they have a unique solution.
- If a₁/a₂ = b₁/b₂ = c₁/c₂ then they are Consistent and dependent lines or Coincident lines and they have infinitely number of many solutions.
- If a₁/a₂ =b₁/b₂ ≠ c₁/c₂ then they are Inconsistent lines or Parallel lines lines and they have no solution.