What change was made to make 3cm/8cm = 9cm/x into a valid proportion

hello :

70y^8 + 30y^6 = 2 ( 35 y^8 + 15y^6)

the lenght is : 35 y^8

the width is : 15y^6

“ a line segment that has the endpoints on the circle and passes through the midpoint is called the diameter. the diameter is twice the size of the radius. a line segment that has its endpoints on the circular border but does not pass through the midpoint is called a chord. a circle is the same as 360 small circle up the number 0 . i hope this .