To verify if $y=\frac{3}{5}$ is a valid solution to the linear equation $5y+3=10y-4$, apply the three-step determination strategy:

Step 1. Substitute the value for the variable: 5\left(\frac{3}{5} ight) + 3 = 10\left(\frac{3}{5} ight) - 4

Step 2. Simplify expressions on both sides. Multiply first: $3 + 3 = 6 - 4$. Then simplify: $6 = 2$.

Step 3. Determine if the result is true: Since $6 = 2$ is a false mathematical statement, the value $y=\frac{3}{5}$ is confirmed as not a solution to the equation.