Answer:

Step-by-step explanation:

Apply exponent rule: 


60 grades in 10 minutes
So 6 grades in 1 minutes
11:00 to 11:40=40 minutes
So 6×40=240 grades in 40 minutes
Answer:
x= -2, y = -3
Step-by-step explanation:
1. substitute x = 4+2y in the first equation: 
simplify it : 
2. isolate y in 8 + 5y = -7 --> 5y = -7 - 8 -->
3. solve for y: 5y = -15 --> y = -15/5 --> y= -3
4. solve for x: x = 4 + 2y
x = 4 + 2(-3)
x = 4 + (-6)
x = -2
what are the options for this question?