Given equations are,

----------------(1)

---------------(2)

The first equation is  solved for y,

                      (First equation)

      (Add 5x to each side)

         (Apply commutative property: )

                    (Apply additive inverse property: )

                          (Apply additive identity property: )

                     (Divide each side by 4)

                          (Cancel common terms)

                         (Simplify)

                             (Divide: )

Substitute for y in the second equation.

                         (Second equation)

           (Substitute  )

Apply distributive property: .

                     (Multiply: )

                               (Apply additive inverse property: )

                                  (Apply subtraction identity property: )

This statement is identity, such that

Hence,there are infinite number solutions.

There are infinite number solutions.