BD = AC/2
4x+2 = (5x+13)/2
2(4x+2) = 5x+13
8x + 4 = 5x+13
8x - 5x = 13 -4
3x = 9
x = 3
In this situation, it is similar to a coin flip, so think about flipping a 2 sided chip, one side colored yellow the other blue, flipping the chip will result in a 50/50 chance for it to land on either side, so no matter how many times you flip it it will always be a 1/2 chance of it being on one of the sides

we know that 7*7=49 so thus


therefor n=2
it is written as