Unit rate is a ratio between two different units with a denominator of one. When we divide a fraction's numerator by its denominator, the result is a value in decimal form. For example: 8/4 = 2 and 3/6 = 0.5. When we write numbers in decimal form, we can write them as a ratio with one as the denominator.
For example, we can write 2 as 2/1, and 0.5 as 0.5/1. However, since that approach can be a little clumsy, we usually drop the one. That said, it's important to remember the one is there, especially when working with unit rates.
For instance, 8 miles/4 hours = 2 miles/hour. Notice again that, while we did not include the 1, we did include the unit 'hour' Miles per hour is a familiar expression, as are unit rates such as:
interest/amount invested
revolutions/minute
salary/year
Conversationally, the word ''per'' indicates we are using a unit rate.
<h3>Rate of the boat in still water is 70 km/hr and rate of the current is 15 km/hr</h3><h3><u>Solution:</u></h3>
Given that,
A motorboat travels 165 kilometers in 3 hours going upstream and 510 kilometers in 6 hours going downstream
Therefore,
Upstream distance = 165 km
Upstream time = 3 hours
<h3><u>Find upstream speed:</u></h3>

Thus upstream speed is 55 km per hour
Downstream distance = 510 km
Downstream time = 6 hours
<h3><u>Find downstream speed:</u></h3>

Thus downstream speed is 85 km per hour
<em><u>If the speed of a boat in still water is u km/hr and the speed of the stream is v km/hr, then</u></em>
Speed downstream = u + v km/hr
Speed upstream = u - v km/hr
Therefore,
u + v = 85 ----- eqn 1
u - v = 55 ----- eqn 2
Solve both
Add them
u + v + u - v = 85 + 55
2u = 140
u = 70
<em><u>Substitute u = 70 in eqn 1</u></em>
70 + v = 85
v = 85 - 70
v = 15
Thus rate of the boat in still water is 70 km/hr and rate of the current is 15 km/hr
Answer:
$109.99
Step-by-step explanation:
You just have to multiply 10x10.99
Answer:
5y = x + 11
Step-by-step explanation:
Given parameters:
Equation of the line ;
y = -5x + 1
Coordinates = (2, -1)
Find the equation of a line perpendicular;
Solution:
A line perpendicular to y = -5x + 1 will have slope that is a negative inverse of the given one.
Equation of a straight line is expressed as;
y = mx + c
y and x are the coordinates
m is the slope
c is the y-intercept
So, the slope of the new line perpendicular is
;
Now let us find the y-intercept of the new line;
x = -1 and y = 2
2 =
x (-1) + c
c = 2 +
=
The equation of the new line is;
y =
x +
or multiply through by 5;
5y = x + 11
Simplify the expression:
7 - 5x - (3 + 5x)
Operate the parentheses. Each term changes its signs because the minus sign represents a -1:
7 - 5x - (3 + 5x) = 7 - 5x - 3 - 5x
Collect like terms:
7 - 5x - (3 + 5x) = 7 - 3 -5x - 5x
Simplify:
7 - 5x - (3 + 5x) = 4 - 10x
Answer: 4 - 10x