Answer:
The value of y is y=15
Step-by-step explanation:
We have:
AB = 6y – 3, BC = 4y – 5, and CD = 7y – 18
We define the isosceles trapezoid as it has two opposites parallel, the two other opposites legs are equal and also the diagonals are equal.
Here AB = CD
6y-3 = 7y-18
Combine the like terms:
18-3 = 7y-6y
15 = y
It means the value of y is y=15....
A quadrilateral, has 4 sides and its internal angles sum, add up to 360, now... you have 3 angles give.. .but we don't have C
so.. C is the difference of all the three angles from 360 or

whatever that is, now, you'll get some value in x-terms
so.... now once we know what C is
you can if you want, do a search in google for "inscribed quadrilateral conjecture", I can do a quick proof if you need one
but in short, for a quadrilateral inscribed in a circle, each pair of opposites angles are "supplementary angles", namely they add up to 180°
so.. what the dickens does all that mean? well D+B=180 and A+C = 180
now. we know what A is, 2x+1
and by now, you'd know what C is from 360-x-2x-1-148
so... add them together then and

solve for "x"
Since it’s a square all sides are even. Meaning you multiply 7/12 by 4. Giving you 7/3 or 2 ⅓. Hope this helps!
May be you know it or not a two dimensional vector can be represented by a complex number.Why i have written this statement you will just know when you will see its solution
a = 3i + mj and b = 2i - nj are perpendicular to each other ,so their dot product
will be zero.
j
vector b = 2i - nj and vector c = ni + 8j are parallel to each other.
j
mn = 6
so m=6/4i
m=3/2i
m=3i^{4}/2i
m = 3i^{3}/2
m= -3i/2 as(i^{4} =1, i^{3} = -i[/tex][/tex]