-2а+3b-8a+7b

To simplify the expression \(-2a + 3b - 8a + 7b\), you can combine like terms:

1. Combine the \(a\) terms: \[ -2a - 8a = -10a \]

2. Combine the \(b\) terms: \[ 3b + 7b = 10b \]

Putting it all together, the simplified expression is: \[ -10a + 10b \]

You can also factor this expression if desired: \[ -10(a - b) \]

So the final answer is either: \[ -10a + 10b \quad \text{or} \quad -10(a - b) \]