Can someone help me please

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

Afactory buys 10% of its components from suppliers b and the rest from supplier c. it is known that 6% of the components it buys are faulty. of the components brought from suppliers a,9% are faulty and of the components bought from suppliers b, 3% are faulty. find the percentage of components bought from supplier c that are faulty.

When steve woke up. his temperature was 102 degrees f. two hours later it was 3 degrees lower. what was his temperature then?