I got x=2.64 or x=1.32 i don't know if i done it right
Answer:

First tangent line:

Second tangent line:

Notice: slope of -1 means that both
are equal to -1, so 
Answer:
see explanation
Step-by-step explanation:
Given A is directly proportional to r² then the equation relating them is
A = kr² ← k is the constant of proportion
To find k use the condition when r = 5, A = 75 , then
75 = k × 5² = 25k ( divide both sides by 25 )
3 = k
A = 3r² ← equation of proportion
(a)
when r = 4, then
A = 3 × 4² = 3 × 16 = 48
(b)
when A = 147 , then
147 = 3r² ( divide both sides by 3 )
49 = r² ( take the square root of both sides )
r =
= 7
Answer:
4√5
Step-by-step explanation:
Use Pythagorean theorem
a^2=21^2-19^2
a^2=441-19^2
a^2=441-361
a^2=80
a= √80
simplify
Midpoint formula: (x1+x2/2 , y1+y2/2)
So, (-1+3/2 , 9+8/2)
-2/2 = -1 17/2 = 8.5
Answer: (-1,8.5)