Let the speed for the first 12 mi be x mi/h, the speed for 18 mi was (x+4) mi/h
thus given that
time=distance/speed
the average time will be:
3=(12+18)/(x+x+4)
3=30/(2x+4)
solving for x we get
3(2x+4)=30
6x+6=30
6x=24
x=4 mi/hr
Answer: 12 mi/hr
Just draw one empty circle for 1 and then a filled circle for -1 so then it's 1-1 which equals 0
Answer:
it was right but ok
Step-by-step explanation:
First find the total number
6+4+5+3 = 18
6th graders : total
4 : 18
Divide each side by 2
4/2: 18/2
2 : 9
Answer:
Complementary angles.
Step-by-step explanation:
Notice that 
and 
, by given.
, by sum of angles.
, by supplementary angles definition.
Which means,
Therefore,
, in other words, angles a and b are complementary by definition.
Answer:
rational
Step-by-step explanation:
-4+0.8=-3.2
