5y = 4x + 20
- 4x + 5y = 20
Answer:
Step-by-step explanation:
Given: The radius of circle O is r, and the radius of circle X is r'.
To prove: Circle O is similar to circle X.
Proof: Move the center of the smaller circle onto the center of the largest circle. Translate the circle X by the vector XA onto circle O. The circles now have the same center.
A dilation is needed to increase the size of circle X to coincide with the circle O. A value which when multiplied by r' will create r.
The scale factor x to increase X:
⇒
A translation followed by a dilation with scale factor will map one circle to the other, thus proving the given both circles similar.
Therefore, circle O is similar to circle X.
Step-by-step explanation:
Answer: We should add the constant 81 to the expression to have a perfect square trinomial.
The perfect square trinomial that would be formed would result from (x + 9)^2.
We can use foil to prove it.
(x + 9)(x + 9)
x^2 + 9x + 9x + 81
x^2 + 18x + 81
81 is the value that must go with 18x in the middle to form the perfect square trinomial.
Answer:hello :
tanA = sinA/cosA
cosA = sinA /tanA
cosA =(4/5)/(4/3)
cosA=3/5
Step-by-step explanation: