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
x-60 is the length. Multiply you get x2-110x=3000 this is a quadratic equation.
Remember to follow PEMDAS, and to only combine terms with like variables.
First, distribute the 2 to all terms within the parenthesis:
2(2p + 4t) = 2(2p) + 2(4t) = 4p + 8t
3 + 4p + 8t, or (D), is your answer choice, for it cannot be simplified anymore.
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3/4 divided by 1/8 would be 6 so Emma can fill 6 bags. Hope this helps and please mark brainliest!
The answer to -7 +11 -6 + 8 =6
