Answer: 5(7+6s-9t)
Explanation:
(note, this isn't the only expression that is equivalent but it's one of them)
You can notice that 35, 30, and 45 share a common factor of 5, and 5x7=35, 5x6=30, and 5x(-9)=-45, so:
5(7+6s-9t), which when you expand, it's equal to= 35+30s-45t