From 1200 midnight to 6:00 am, the temperature decreased by 12°C. if the original temperature was 12°C, which expression can be used to represent the situation?
A
12-12
B
12-12
C 12-(-12)
D
-12 + (-12)

50 will mark show all use the linear combination method to solve the system of equations. explain each step of your solution. if steps are not explained, you will not receive credit for that step. 2x+9y= -26 -3x-7y=13