The problem is to factor the expression $25y + 6x - 30 - 5yx$.

1. Problem Description

The problem is to factor the expression $25y + 6x - 30 - 5yx$.

2. Solution Steps

We can rearrange the terms and factor by grouping:

$25y + 6x - 30 - 5yx = 25y - 5yx + 6x - 30$.

Now, we can factor $5y$ from the first two terms and $6$ from the last two terms:

$5y(5 - x) + 6(x - 5)$.

Notice that $(5-x)$ and $(x-5)$ are negatives of each other, so we can rewrite $6(x-5)$ as $-6(5-x)$.

$5y(5 - x) - 6(5 - x)$.

Now we can factor out $(5 - x)$ from both terms:

$(5 - x)(5y - 6)$.

3. Final Answer

$(5-x)(5y-6)$