Answer:
53.33 mph
Step-by-step explanation:
Speed is the rate of change of distance with time. Mathematically,
speed = distance/time
and is measured in miles per hour or meter per second.
To get the average speed over the entire trip, we must get the total time spent on trip and the total distance, then apply the speed formula
Time for the first 300 miles
= 300/60
= 5 hours
Time spent on the last 100
= 100/40
= 2.5 hours
Total time of the trip = 5 + 2.5
= 7.5 hours
Total distance covered
= 300 miles + 100 miles
= 400 miles
Average speed on the trip
= 400/7.5
= 53.33 miles per hour
Roughly what I gave your doppelganger (you + 1) a few minutes ago . . .
[ (4 + 3)² - 1 ] divided by (7 - 3) .
Cramer's rule works as follows:
x+3y=16
3x+y=8
Then
x=Dx/D
y=Dy/D
where Dx,Dy,D are 2x2 matrices formed from of coefficients and right hand side.
D=
1 3
3 1
=1-9=-8
Dx=matrix D with first column replaced by the vector [16,8]=
16,3
8 1
=16-24
=-8
Dy=matrix D with second column replaced by the vector [16,8]=
1 16
3 8
=8-48
=-40
Therefore
x=-8/-8=1
y=--40/-8=5
Check:
x+3y=1+3(5)=16
3x+y=3(1)+5=8 ok.
Step-by-step explanation:
why ? you did it right there already.
the numerator is the top part of the fraction, the "counting" part (how many units of a certain type or size are there).
the denominator (the bottom part) is defining the type or size of units described by the fraction.
so, we are adding 4 to the numerator of 2/5, making it (2+4)/5 = 6/5
what do we need to add to the denominator (the bottom part) to make the fraction have the value of 1/2 ?
so, what x would make 6/x = 1/2 ?
6 = x/2
x = 6×2 = 12
so, we need to get 12 in the denominator, where we have currently 5.
therefore, we need to add 12-5 = 7 to it.
so that
6/(5+7) = 6/12 = 1/2
