Write sum-of-products and product-of-sums expressions

Question

Solve the following problem:

Consider the function f(x₁, x₂, x₃) given by the set of decimals indices corresponding to the 1-minterms {2, 4, 7}. Write the Sum-of-products and Product-of-sums expressions for f. Notice that the list of decimal indices corresponding to 1-maxterms consists of numbers which do not appear in the list of decimal indices for 1-minterms.

Make sure you use enough details to support your answer.