Question

H2SO4+B(OH)3=B2(SO4)3+H2O

Answer 1

I asssume you want me to balance that.
How about trying
3 H2SO4
2 B (OH)3
1 B2(SO4)3
6 H2O

Answer 2

Now the how and why:
I said I will have x B2(SO4)3 molecules
Then I must have 2x B(OH)3 molecules
I assume I have y H2O molecules
Then I have 2 Y H atoms on the right
but on the left I have 3 x H2SO4 molecules to balance 3 x sulfur on the right
and I have 2 x B(OH)3 molecules on the left to balance B
so
I have 6x + 6x or 12 x H atoms on the left to balance my 2 y H atoms on the right
12 x = 2 y
6 x = y
so I tried x = 1 and y =6 and it balanced