12 + 6x + 6x + 6y = 12 + 12x + 6y
Answer:

Step-by-step explanation:
since a=lw, the area is (x^2-3x+7)(x+4)
1. distribute parentheses 
2. apply +(-a)=-a rule 
3. Simplify
Steps to simplify:





4. Add like terms 
5. Add like terms 
Answer:
The approximate distance is 15416 miles....
Step-by-step explanation:
We have given:
A satellite is 19,000 miles from the horizon of earth.
The radius is 4,000 miles.
Lets say that BC =x
AO = OB = 4,000 miles
AC = 19,000 miles
The tangent from the external point forms right angle with the radius of the circle.
So in ΔABC
(OC)² = (AC)²+(OA)²
where OC = x+4000
AC = 19,000
OA = 4000
Therefore,
(x+4000)² = (19,000)² +(4,000)²
Take square root at both sides:
√(x+4000)² = √(19,000)² +(4,000)²
x+4000 =√361000000+16000000
x+4000 = √377000000
x+4000 = 19416.48
x= 19416.48 - 4000
x = 15416.48
Therefore the approximate distance is 15416 miles....
Problem 215
Check out the attached image. Line up the letters ABC and CDE so the first set of letters are over the second set of letters. Order is important here. Note how A corresponds to C (second C), B corresponds to D, and (the first) C corresponds to E.
We have this mapping:
A <--> C
B <--> D
C <--> E
This means...
Angle BAC corresponds to Angle DCE (red angles)
Angle ABC corresponds to Angle CDE (blue angles)
Angle BCA corresponds to Angle DEC (green angles)
It also means...
Side BC corresponds to Side DE (red sides)
Side AC corresponds to Side CE (blue sides)
Side AB corresponds to Side CD (green sides)
Check out the attached image which I hope clears up any confusion you may have. Often I think it helps to represent stuff like this in a visual way.
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Problem 216
Answer: True
Since triangle ABC is congruent to triangle DEF, this means that side AB is congruent to side ED. These are corresponding sides. Since AB = 6, this means ED = 6 as well.
Answer:
The answer would be:
B. ∠DEC is an exterior angle.
Step-by-step explanation: Your welcome