Answer:
the answer is F (-7,-1) and D(1,7)
Answer: The answer is either 90
Step-by-step explanation:
you multiply 15 by 12 then divide by 2 to get 90 brainliest plz??
Time for entire trip = 2d/30 hours
Time for first part of trip = d/60.
Time for second part of trip, is given by:

Therefore the speed during the second distance d is 20 mi/h.
Y -3x = 7 from this result y = 7 +3x what value of y we need substituting in place of y inside second equation and will get
21 +9x = 3y
21 +9x = 3(7 +3x)
21 +9x = 21 +9x
0 = 0
so this mean that there are an infinite number solutions so choice B. is right