I am a bit lost on how my teacher got the answers for the stuff not circled in blue. Can anyone explain it to me? Thanks. I will reward more points to whoever explains it the best.

Aiden buys two bags of chips at $1.09 each and a 20 ounce soda for $1.20 at the gas station. he knows that the state tax is 5.5. how much change will he receive from a $5 bill?

The magnitude, m, of an earthquake is defined to be m=log l/s, where i is the intensity of the earthquake (measured by the amplitude of the seismograph wave) and s is the intensity of a “standard” earthquake, which is barely detectable. what is the magnitude of an earthquake that is 1,000 times more intense than a standard earthquake? use a calculator. round your answer to the nearest tenth.

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way