Answer:
option D
Step-by-step explanation:
x-2y≥-12
-2y≥-x-12
y≤0.5x+6
has to be a solid line since y is less than or equal to 0.5x+6
so, options 1 and 3 are not applicable
also, in y≤0.5x+6 , y is less than or equal to this line, thus it only exists on the line and to the right of it (below it)
so, option 2 is wrong also, leaving us with option 4 or D, which in this case is the answer
I attached a file of this inequality's graph to prove my answer once more
1.5x+x=1380
2.5x=1380
x=552 miles
A is the solution.
<span>A freight train completes its journey of 150 miles 1 hour earlier if its original speed is increased by 5 miles/hour. What is the train’s original speed?
***
let x=original speed
x+5=increased speed
travel time=distance/speed
..
lcd:x(x+5)
150(x+5)-150x=x(x+5)
150x+750-150x=x^2+5x
x^2+5x-750=0
(x-25)(x+30)=0
x=25
What is the train’s original speed? 25 mph</span>