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:
if a·b=0, then either a=0 or b=0, or both
Step-by-step explanation:
just answered it on apex :)
Answer:
the answer is 3.
Step-by-step explanation:
Difference between means to subtract.
8 - 5 = 3
Answer:
Our rate is, 10:125
Let's make it a unit rate!
Divide by 10 on both sides:
1:12.5
Step-by-step explanation:
She makes 12.50 dollars per hour.
Answer:
1. b.
2. a.
3. b.
4. d.
5. a.
6. b.
7. c.
8. b.
9. b.
10. c.
11. a.
12. b.
13. a.
14. c.
Step-by-step explanation:
7 + 3 = 10
+ 679 - 2056 = -1377
- 398 + 1 = -397
-23 - 237 = 260
2 - 6 = -4
-2 × 3 × -4 = 24
absolute value of -36 = 36
6 + 4 = 10
- 5928 - 965 = -6893
215 × 212 + 212 × 314 = 112148
(15 + 5) ÷ (15 + 5) = 20 ÷ 20 = 1
-457 + 1 = -456
- 218 -1 = -219
