There are 20 miles is Sheng from his home.
Answer:
x=291/76
Step-by-step explanation:
Convert:
1/2x(6x+ 1/2)=-0.8x+16-1.2
Remove parenthesis and move terms:
3x+1/4=-0.8x+14.8
Collect the like terms and convert:
3x+0.8x=14.8-1/4
Subtract the fractions:
3.8x=74/5-1/4
Divide both sides by 3.8:
3.8x=291/20
x=291/76
There will be eight marbles on the 9th line
Answer: -3/2
Step-by-step explanation:
The axis of symmetry, and thus the x-coordinate of the vertex, is given by 
So, the answer is 