Help me please this is a quiz for today

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

Tabby sells clothing at a retail store, and she earns a commission of 6.25% on all items she sells. last week she sold a pair of jeans for $32.50, a skirt for $18.95, and 2 blouses for $14.95 each. what was tabby's total commission? a $4.15 b $5.08 c $81.35 d $348.60

Solve each quadratic equation by factoring and using the zero product property. n^2 - 49 = 0