Question

4x-3y+7=0 and 7x+8y+9=0 solve it by eliminating method​

Answer 1

Taking determinant of co-efficient of x,y and z
∣
∣
∣
∣
∣
∣
∣
∣
​

4
7
8
​

−3
−8
−6
​

1
10
2
​

∣
∣
∣
∣
∣
∣
∣
∣
​

R
3
​
→R
3
​
/2
∣
∣
∣
∣
∣
∣
∣
∣
​

4
7
4
​

−3
−8
−3
​

1
10
1
​

∣
∣
∣
∣
∣
∣
∣
∣
​

R
1
​
=R
3
​

∴ determinant is 0
∴ equation has infinite solutions.