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:
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Step-by-step explanation:
Answer:
-52/75
Step-by-step explanation:
Answer:
The fourth choice
24.2° and 114.2°
Step-by-step explanation:
Complementary angles add up to 90°
Supplementary angles add up to 180°
*a trick to remember this is to know that C is before S in the alphabet, and 90 is before 180, so Complementary is 90 and Supplementary is 180
Step 1: Find the complementary angle
Take 90° and subtract the give angle to find the angle you would need...
90° - 65.8° = 24.2°
Step 1: Find the supplementary angle
Take 180° and subtract the give angle to find the angle you would need...
180° - 65.8° = 114.2°
Answer:
See how X looks similar to a obtuse angle? The angle looks an awful lot like it's around 40 degrees though, it seems to be an acute angle, they are less than 90* so anything near 90 should make sense. I'd say exactly 45.
Step-by-step explanation: