In the accompanying figure. abcd is a square. latex: ab=5x-10 a b = 5 x − 10 and latex: bc=2x+20. b c = 2 x + 20. find the value of x.

x = 10

Explanation:
A square is a quadrilateral in which all sides are equal.

We are given that:
ABCD is a square
AB = 5x - 10
BC = 2x + 20

Since we're talking about a square, therefore:
AB = BC
5x - 10 = 2x + 20
5x - 2x = 20 + 10
3x = 30
x = 30/3
x = 10

Now, we can check our solution:
AB = 5(10) - 10 = 40 units
BC = 2(10) + 20 = 40 units
We can see that both sides are equal

Hope this helps :)