The equations 3x - 4y = 5 and 12x - 16y = 20 have:

Concept: 

If two linear equations

a₁​x + b₁y ​= c₁​ and a₂​x + b₂y ​= c₂​. Then,

(a) If a₁​​/a₂ = b₁​​/b₂ ​​= c₁​​/c₂ ​​, the system is consistent and has infinitely many solutions.

(b) If a₁​​/a₂ = b₁​​/b₂ ≠ c₁​​/c₂ the system has no solution and is inconsistent

Calculation:

In equations 3x − 4y = 5 and 12x − 16y = 20

3/12 = -4/-16 = 5/20 ⇒ ¼ = ¼ = ¼

So the system is consistent and has infinitely many solutions 

∴ They have more than two common solutions.