block diagram help

Hey. I need to find the differential equation expressed by this block diagram. Can anyone help me? I can't seem to figure it out. Thanks in advance.

picture attached to post

also for whoever helps me out could you please show me in steps how to do it so I can figure out what I am doing wrong. Thanks

Call the output of the left summer a.

Then, a= x(t) - y(t) +∫3y(t) {Left summer}

And, y(t) = 5a + ∫a

I'll let you substitute and simplify.

ok I understand that but how would I get rid of the integral of y(t)? Is there a way to eliminate all integrals from the answer?

cuz you get

Y(t)=(5X(t) - 5Y(t) + 15∫Y(t) )+ (∫ (X(t) - Y(t) + 3∫Y(t)))

then what