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:
Area of composite figure = 216 cm²
Hence, option A is correct.
Step-by-step explanation:
The composite figure consists of two figures.
1) Rectangle
2) Right-angled Triangle
We need to determine the area of the composite figure, so we need to find the area of an individual figure.
Determining the area of the rectangle:
Given
Length l = 14 cm
Width w = 12 cm
Using the formula to determine the area of the rectangle:
A = wl
substituting l = 14 and w = 12
A = (12)(14)
A = 168 cm²
Determining the area of the right-triangle:
Given
Base b = 8 cm
Height h = 12 cm
Using the formula to determine the area of the right-triangle:
A = 1/2 × b × h
A = 1/2 × 8 × 12
A = 4 × 12
A = 48 cm²
Thus, the area of the figure is:
Area of composite figure = Rectangle Area + Right-triangle Area
= 168 cm² + 48 cm²
= 216 cm²
Therefore,
Area of composite figure = 216 cm²
Hence, option A is correct.
The equations y = -x -3 and 5y + 5x = -15 represents the same line option 'the same line' is correct.
<h3>What is linear equation?</h3>
It is defined as the relation between two variables, if we plot the graph of the linear equation we will get a straight line.
If in the linear equation, one variable is present, then the equation is known as the linear equation in one variable.
We have two equation of the line:
y = -x -3 and
5y + 5x = -15
From the equation 5y + 5x = -15:
Divide by 5 on the above equation:
y + x = -3
or
y = -x -3
The two equations y = -x -3 represents the same line.
Thus, the equations y = -x -3 and 5y + 5x = -15 represents the same line option 'the same line' is correct.
Learn more about the linear equation here:
brainly.com/question/11897796
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Answer:
10
Step-by-step explanation:
The answer is 0.1538461538 but you round it to the nearest tenth that gives you 0.2
