Let the distance to his office be x, then
On monday, speed = x/20 miles per minutes = 3x miles per hour
On tuesday, speed = (3x + 15) miles per hour
Time = distance / speed
(20 - 6)/60 hours = x/(3x + 15) hours
7/30 = x/(3x + 15)
7(3x + 15) = 30x
21x + 105 = 30x
30x - 21x = 105
9x = 105
x = 105/9 = 11.7 miles
Therfore he travels an average of 11.7 miles to work.
3\4a=24 multiply both sides by 4 to get rid of 4(4 x 24=96)
3a=96 divide both sides by 3 to remain with a
a=32
We are given the expression:
U = E * P
The equality symbol “ = “ means that for all cases, the
value of U and E * P must always be equal. This means that whatever happens on
the left side, must equally happen on the right side.
So what this actually means is that, if we double U so we
must also double the expression E * P, that is:
2 U = 2 (E * P)
However since P stays constant in the process, therefore
only E is changed, hence:
2 U = P * 2 E
So we can see that E is also doubled.