Using similarity triangle theorem
DB/ BE= AD/CE
DB = 6
BE = x + 1
AD = 4
CE = x
Substitute the above values into the above formula
6/x+ 1 = 4/x
Cross multiply
6 * x = (x + 1) * 4
6x = 4x + 4
Collect the like terms
6x - 4x = 4
2x = 4
Divide both sides by 2
2x/2 = 4/2
x = 2
The answer is 2