Lets see whether the river is going against the boat or with it
speed=distance/time
22 miles per 1.5 hour
speed=22/1.5=14.66666 mile per hour
50mph>14.6666666mph
ok it slowed down, so it it going agains the current
boatspeed-currentspeed=realspeed
realspeed=14.666666mph
boatspeed=50mph
50-curretn speed=14.66666666666666
50 both sides
-currentspeed=-35.33333333333333
multiply -1
currentspeed=35.33333333333333mph
the current is 35 and 1/3mph agains the boat
Answer:
D
Step-by-step explanation:
Here, we want to get the equation of the line perpendicular to;
y = -3x + 2
From here, we can compare with the standard form of the equation of a straight line which is;
y = mx + c
From here m = -3
The slope is -3
Now, if two lines are perpendicular, the product of their slopes is -1
Thus;
-3 * m = -1
m = 1/3
So we want to select an equation out of the options that has a slope of 1/3
Let us take a look at the last option
x -3y = 3
3y = x-3
divide through by 3
y = x/3-1
So here the coefficient of x is 1/3 which is the slope of the perpendicular line that we are looking for and is our slope
I did another one just like this about an hour ago. I did it the elegant, tedious way,
and it took about 2 feet of screen. Then I realized there was a totally bourgeois but
easy way to do it. For 5 points, I'll give you the method for the masses:
List all the possible pairs of digits that add up to 9, along with their flips:
18 . . . . . 81
27 . . . . . 72
36 . . . . . 63
45 . . . . . 54
Do you see any pair that are different by 27 ?
How about 36 and 63 ?
So the original number is 63, and when you flip it, it becomes 36, which is 27 less.