a. The first variable is x and the second variable is y.
b. The equations are 
and 
Step-by-step explanation:
Step 1:
The first step is to define the variables. The variables can be any two symbols, letters, characters, etc.
Here let the first variable be x and the let the second variable be y.
So the variables are defined as x and y.
Step 2:
The sum of the given variables is 12.
The first variable + the second variable = 12,
The difference between the two variables is 4.
The first variable - the second variable = 4.
Step 3:
If we add both the equations we get, 
and 
x = 8 and y = 4.
Answer:
You are a rectangular prism.
Step-by-step explanation:
Rectangular prisms fill the criteria you described: two triangular faces, three rectangular faces, 6 vertices, and 9 edges. Thus, the answer is correct.
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Answer:
The variable, y is 11°
Step-by-step explanation:
The given parameters are;
in triangle ΔABC; 
in triangle ΔFGH;
Segment 
= 14 Segment 
= 14
Segment 
= 27 Segment 
= 19
Segment 
= 19 Segment 
= 2·y + 5
∡A = 32° ∡G = 32°
∡A = ∠BAC which is the angle formed by segments = 14 and = 19
Therefore, segment = 27, is the segment opposite to ∡A = 32°
Similarly, ∡G = ∠FGH which is the angle formed by segments = 14 and = 19
Therefore, segment = 2·y + 5, is the segment opposite to ∡A = 32° and triangle ΔABC ≅ ΔFGH by Side-Angle-Side congruency rule which gives;
≅ by Congruent Parts of Congruent Triangles are Congruent (CPCTC)
∴ = = 27° y definition of congruency
= 2·y + 5 = 27° by transitive property
∴ 2·y + 5 = 27°
2·y = 27° - 5° = 22°
y = 22°/2 = 11°
The variable, y = 11°
Hello,
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Answer B
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2x²+28x-5=2(x²+2*7x+49)-5-2*48
=2(x+7)²-103
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