Trevor earns $7.80 an our take-home pay and works 20 hours each week to buy a new laptop computer to take to college that cost $780 how many weeks will it take for church to achieve his goal

He makes 7.80 per hrand works 20 hrs per weekso he makes 
7.80 * 20 = 156 per week

156x = 780where x stands for the number of weeks
x = 780/156
x = 5 <== so it will take him 5 weeks to achieve his goal of having enough money to buy the computer