Answer:
- The system of equations is x + y = 85 and 7/20x+2/5y=31
- To eliminate the x-variable from the equations, you can multiply the equation with the fractions by 20 and multiply the other equation by -7.
- B-She used 60 minutes for calling and 25 minutes for data.
Step-by-step explanation:
It is always a good idea to start by defining variables in such a problem. Here, we can let x represent the number of calling minutes, and y represent the number of data minutes. The the total number of minutes used is ...
x + y = 85
The total of charges is the sum of the products of charge per minute and minutes used:
7/20x + 2/5y = 31.00
We can eliminate the x-variable in these equations by multiplying the first by -7 and the second by 20, then adding the result.
-7(x +y) +20(7/20x +2/5y) = -7(85) +20(31)
-7x -7y +7x +8y = -595 +620 . . . . eliminate parentheses
y = 25 . . . . . . . . simplify
Then the value of x is
x = 85 -y = 85 -25
x = 60
Answer:
The equation of line with given slope that include given points is 3 y + x - 20 = 0
Step-by-step explanation:
According to Cora , if we know the slope and points on a line then we can write the equation of a line .
Since , The equation of line in slope-intercept form is
y = m x + c
<u>Where m is the slope of line , and if we know the points ( x , y ) which satisfy the line then constant term c can be get and the equation of line can be formed .</u>
So , From the statement said above it is clear that she is correct .
Now , Again
Given as :
Slope of a line is m = - 
That include points ( 2 , 6 )
Now from the equation of line as y = m x + c
∴ 6 = -
( 2 ) + c
Or, 6 = -
+ c
So , c = 6 +
or, c =
∴ c =
So, The equation of line can be written as
y = -
x +
Or, 3 y = - x + 20
I.e 3 y + x - 20 = 0
Hence The equation of line with given slope that include given points is 3 y + x - 20 = 0 Answer
The answer to your question is D.
D. Expenses for a birthday party are not a fixed expense.
By definition, a fixes expense is a bill or something that won't change in the amount of payment. A car payment will always be the same each month; the mortgage will always be the same and car insurance will always be the same each month.
decrease in temperature if you hike up the mountain 3000 meters is
° .
<u>Step-by-step explanation:</u>
Here we have , Hiking up a mountain, you notice that the air temperature drops 10 degrees every 1000 meters increase in elevation . We need to find Write a multiplication expression to represent the decrease in temperature if you hike up the mountain 3000 meters. Let's find out:
For every 1000 meters rise in elevation , there is decrease in 10° of temperature . So , For rise in n meters in elevation , there is decrease in n×10° of temperature i.e
Decrease in temperature = (n/1000)×(-10) i.e.
⇒ (n/1000)×(-10)
⇒ 
At n = 3000 meters:
⇒ 
⇒ 
⇒
°
Therefore , decrease in temperature if you hike up the mountain 3000 meters is
° .