'come up with a solution' is correct and usable in written English. You can use this phrase in a variety of contexts to suggest that one should find a solution for a problem or issue. For example, "We need to come up with a solution to this budgeting issue quickly."
"We come up with a solution, but it depends on who acts on it," she said.
My team has come up with a solution that we call "the 9% Solution".
So people have come up with a solution.
I'm sure they can come up with a solution".
The next mayor has to come up with a solution".
Here, you've got to also come up with a solution.
But they have yet to come up with a solution.
"Most people just try and come up with a solution.
And they just refused to come up with a solution".
Can the architects come up with a solution?
And in fact, all these years later, they had come up with a solution.
Awesome tool! I started using it one year ago and I never had to look for another app
Ha Thuy Vy
MA of Applied Linguistic, Maquarie University, Australia