#8: $900. (I found this answer by multiplying 3000 and 0.3 by the way)
#9: 160 miles. I found this answer by multiplying 80 by two, since two halves/50% make a whole or 100%.
1.8- 3.7x = 4.2x + 0.3
Move 4.2x to the other side
Sign changes from +4.2x to -4.2x
1.8-3.7x-4.2x= 4.2x-4.2x+0.3
1.8-3.7x-4.2x= 0.3
1.8-7.9x= 0.3
Move 1.8 to the other side
Sign changes from +1.8 to -1.8
1.8-1.8-7.9x= 0.3-1.8
-7.9x= 0.3-1.8
-7.9x= -1.5
divide both sides by -7.9
-7.9/-7.9x= -1.5/-7.9
x= 0.18987341
Answer: x= 0.18987341
Answer: the system has no solution
Step-by-step explanation: for a solution to occur the lines have to cross
D: 1/6 * 2 = 2/12
hope this helps :) (please mark brainliest!)