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
Well this is pretty easy.
If there are 8 people, with 6 doughnuts in every box, then do 6*4 to give you 24.
If you know you multiplication (recommend practicing), then you would know that 8 is a multiple of 24. So the second step to this word problem is 24/8 to give you the final answer of:
3 doughnuts / person
Answer:
d. 6
Step-by-step explanation:
Answer:
Step-by-step explanation:
a₁ = πr₁⁵ = 25π cm²
a₂ = 25(25π) = 625π cm²
r₂ = 25 cm
Answer:16.5
Step-by-step explanation:
