Answer:

Step-by-step explanation:
The mass of the products in a chemical reaction must be equal to the reactants mass. As is stablish in the mass conservation law.
First look at the elements present in the equation.

Make a list of the atoms present in each side of the equation.
Then write the quantity ( number) in which they are present:
Si 1 Si 1
O 2 O 1
H H2
F F 4
As you can see, in the product side of the equation you have 4 atoms of Fluorine F, and 2 of hydrogen H, first try to balance by adding a 4 to the reactant HF.
Now you will have to add a leading 4 in the reactants side. But now you need to balance the H and the O.

You will have the following information:
Si 1 Si 1
O 2 O 1
H 4 H2
F 4 F 4
If you add a 2 coefficient in the water you will have everything balanced
