If solving for x you will first need to combine like terms. Then after getting the amount of numbers and amount of x numbers you will divide the x number from both. After doing that you would get X=-10
Initially started 20 feet from the ground .
Went uphill 83 feet.
So: 20 + 83 = 103. The coaster is 103 ft above at this point.
Went down 42 feet
So: 103 - 42 = 61.
Went up 128 feet
So: 61 + 128 = 189
Finally, went down 90 feet
So: 189 - 90 = 99
99 ft above ground.
A. & B. Is the correct answer.
Answer: 11x - y = 8x - y + 3x
D. Hope this helps 13.9027 :)