12a)
5x + 45 + 3x - 25 = 180
8x + 20 = 180
8x = 160
x = 20
12b)
2x - 5 = 2(20) - 5 = 40 - 5 = 35
3x - 25 = 3(20) - 25 = 60 - 25 = 35
y = 180 - (35+35)
y = 180 - 70
y = 110
Answer:
C=6π
Step-by-step explanation:
It is given that, two circles are identical. The radius of first circle is 2x and the diameter of other circle is 2x+3.
If identical, it means that the radius of both circles are same i.e.

Radius of both circles is 2(1.5)=3
The circumference of a circle is given by :

So, the circumference of each circle is 6π.
Answer:
x=3
y=5
Step-by-step explanation:
3×3=9
5×5=25
9+25=34
[3^2+5^2=34]
3^2=9
2×5=10
9+10=19
[3^2+2×5=19]