$-3+5 a=4 a-10$

Step 1 ：Start with the equation \(-3+5a=4a-10\).

Step 2 ：Subtract \(4a\) from both sides to get \(a=-3+10\).

Step 3 ：Simplify to get \(a=7\).

Step 4 ：However, there seems to be a mistake in the initial solution. Let's correct it.

Step 5 ：Start with the equation \(-3+5a=4a-10\).

Step 6 ：Add \(3\) to both sides to get \(5a=4a-7\).

Step 7 ：Subtract \(4a\) from both sides to get \(a=-7\).

Step 8 ：So, the correct solution is \(a=-7\).

Step 9 ：Final Answer: \(\boxed{-7}\)