Hello there, and thank you for posting your question here on brainly.
To find this, you have to find the greatest common factor. (GCF)
GCF = 3
Factor out the GCF: Write the GCF first. Then, in parentheses, divide each term by the GCF.
3 (15t/3 + 6/3)
Simplify.
-3(5t + 2)
Hope this helped! ☺♥