Use Pythagorean Theorem:
a² + b² = c²
"a" is one side of the right triangle.
Its length is: radius of larger circle minus radius of smaller circle: (11 - 3 = 8)
The distance between the center of the circles creates the hypotenuse (17)
8² + b² = 17²
b² = 225
b = 15
Answer: the length of the common external tangent is 15.
Answer:
and 
Step-by-step explanation:
-equation 1
-equation 2
Solving the equation 1 to get the value of
To solve such type of equations that have two unknown variables, find the value of one variable in terms of the other from any one of the equation and put the value in the second equation which will give the value of both the variables
Solving Equation 2 to find x


equation 3
Putting this value of x in the equation 1





, 
Putting the value of y in equation 3 to find the value of x


Step-by-step explanation:
I'm not sure but I think there are 2 terms!