Change 12 out of 40 to a percentage

Question: what is the value of x 4x-2= (-7) +5x. it would be greatly appreciated if someone could actually explain to me step by step

The marriott family bought a new apartment three years ago for $65,000. the apartment is now worth $86,515. assuming a steady rate of growth, what was the yearly rate of appreciation? what is the percent of the yearly rate of appreciation?

You paid 28.00 for 8 gallons of gasoline. how much would you pay for 15 gallons of gasoline?