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:
For question 1 it's B
For question 2 it's C
Step-by-step explanation:
<u>For question 1, you have to apply the "Triangle Inequality Theorem"</u>
A+B > C
B+C > A
A+C > B
Let's say that A=22, B=17, C= 14
22+17 > 14 True
17+14 > 22 True
22+14 > 17 True
Therefore, the answer is B
<u>For question 2, you apply the rule of the sum of the triangles which is 180°</u>
70+70+? = 180
140+? = 180
? = 40
Therefore, it's C
Answer:
it should be 14,580 m^2
(the ^2 means squared btw)
A and C are rational numbers
A graph of a proportional relationship is a straight line that passes through the origin. The constant of a proportionality in a graph of a proportional relationship is the constant ratio of y to x (the slope of the line).
