Solve for a. a + (−5) = 12

Question 2 options:

a = 17

a = 7

a = -12

a = -17

Can someone pls ! pls answer all. no explanation needed..

Jayne is studying urban planning and finds that her town is decreasing in population by 3% each year. the population of her town is changing by a constant rate.true or false?

Awindow washer cleans 42 windows in 2 hours. at this rate, how many windows did he clean in 180 minutes.