Equation 1: 4x - 5y = 20

Equation 2: 3x + 5y = 15

Both the equations are in the form of :

a₁x + b₁y= c₁ & a₂x + b₂y = c₂ where

According to the problem:

a₁ = 4

a₂ = 3

b₁ = -5

b₂ = 5

c₁ = 20

c₂ = 15

We compare the ratios

Since , So

It has a Unique solution