19. The radius of a circle is less than twice the radius of the other by 1 cm. The sum of their areas is 34 π sq cm. Find the radius of each circle.
Answers
Answered by
0
Answer:
Step-by-step explanation:
Answered by
3
Answer:
Step-by-step explanation:
Let the radius of second circle be r and first circle be 2r-1.
Ar. of 1st circle+ Ar. of 2nd circle= 34π
πr^2 + π (2r-1)^ 2 = 34π
π{ r^2 + (2r-1)^2} = 34π
π(r^2 +4r^2+1-4r) = 34π
5r^2 -4r+1-34 =0
5r^2 -4r -33 =0
5r^2-15r +11r -33=0
5r(r-3) +11(r-3) =0
(r-3) (5r+1)=0
r=3 or r= -1/5 ( Radius cannot be negative)
Therefore, radius of 1st circle = 2*3-1=5cm
Radius of second circle =3cm.
Similar questions