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
Answer:
4 mm
Step-by-step explanation:
The radius is half the diameter, so in this case the radius of each button is 4 mm.
3x+2(4x-4)=3 - remove parentheses
3x+ 8x-8=3 - collect like terms
11x- 8 =3 - move the constant to the right
11x=3+8 - calculate
11x = 11 - divide both sides by 11
x= 1
Answer:
B
Step-by-step explanation:
