Solve the following pair of linear equations by the method of elimination: $0.3 x + 0.4 y = 1$ and $6 x + 8 y = 20$.

(N/A) Given equations are:
$1) 0.3 x + 0.4 y = 1$
$2) 6 x + 8 y = 20$
Multiply equation $(1)$ by $10$ to clear the decimals: $3 x + 4 y = 10$ (Equation $3$).
Now,multiply equation $(3)$ by $2$: $6 x + 8 y = 20$ (Equation $4$).
Comparing equation $(2)$ and equation $(4)$,we see they are identical: $6 x + 8 y = 20$.
Since both equations represent the same line,there are infinitely many solutions.
The solution set is $\{(x, y) \mid 3 x + 4 y = 10, x, y \in R \}$.