ΔHf = ∑BE(R) – ∑BE(P).like this what is ΔHc( enthalpy of combustion)

There are formulae that you can make use of to determine ΔHr when given Bond Energy/ΔHf/ΔHc.

When given Bond Energy values
ΔHr = ∑Bond Energy(Bonds Broken) + ∑Bond Energy(Bonds formed)
In this case here, remember to include the signs (bonds broken are +ve and bonds formed are -ve).

When given ΔHf
ΔHr =∑ΔHf(Products) - ∑ΔHf(Reactants)

When given ΔHc
ΔHr =∑ΔHc(Reactants) - ∑ΔHf(Products)