Answer:
6x=54
Step-by-step explanation:
3x - {7-x} =29
open bracket
3x - 7 +x =29
collect like terms and equate
4x =29 +7
4x = 36
divide both sides by 4
x = 9
.
. . 6x= 6 × 9 = 54
6x= 54
Answer:
840
Step-by-step explanation:
8.4x10^2
8.4x100
move the decimal to the right for the amount of zeros :)
840
The correct answer to this problem would be -3. Based on the points you've provided on the graph, -3 would be the correct common difference. :)
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
