Answer:
40 km
Step-by-step explanation:
80 per hour cut in half is 40, it's cut in half because it's half an hour
Multiply each side by 6x.
4x+x = 30
Square both sides.
16x^2+3x^2=900 = 19x^2
x^2= about
x=6.9
________________
The answer is 1/9
_________________