Question

solve by cross multiplication:
2x+y=-1 ; 6x+3y=-3

Answer 1

Step-by-step explanation:

2x+y=-1

2x×1=y×-1

2x=-1

Answer 2

Answer:

x=y=∞

Step-by-step explanation:

we know x/b2c1-b1c2=y/c2a1-c1a2=1/a2b1-a1b2

2x+y+1=0-----(i)

6x+3y+3=0-----(ii)

divide eq (ii) by 3

so 2x+y+1=0-----(iii)

let 2 be a1, 1 be b1, 1 be c1,  2 be a2, 1 be b2, 1 be c2

x/(1×1)-(1×1)  = y/(1×2)-(1×2)  = 1/(2×1)-(2×1)

x/0=y/0=1/0

x/0=∞

y/0=∞

1/0=∞

as we can see that x=y=∞

so there are ∞ number of solutions for the above pair of linear equations.

hope it helps:)