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
A(b + c) = a*(b + c) = a*b + a*c
You must multiply individual terms and see what it would equal
Step-by-step explanation:
Let U=universal set
C=students who drink coke
P = students who drink pepsi
Answer:
Area of the triangle is 10 square units
Step-by-step explanation:
Recall that the formula for the area of a triangle is: "base x height / 2", and in this case, we can consider the triangle's base as the segment that joins the vertices (5, 4) and (5, 8) which gives a segment length of 4 units. The height of the triangle is then the distance between the third vertex (0,7) and the base, which is exactly 5 units. Then the area becomes:
Area = 4 x 5 / 2 = 10 square units.
Answer:For the first one 26.73 would turn into 27 and 89.42 would stay 89
Step-by-step explanation: Any number that is 5 or greater can be used to round any number.
