What is the value of x?me with this math problem.

Short answer x = 10
Remark
An angle bisector divides  (in this case) the base in the same ratio as the two sides.

Formula
8 / 12 = (x + 4)/(2x + 1)

Solve
Reduce the left hand side.
2/3 = (x + 4)/(2x + 1)                Cross multiply
2*(2x + 1) = 3 * (x + 4)             Remove the brackets
4x + 2 = 3x + 12                       Subtract 3x from both sides
4x - 3x + 2 = 12                        Subtract 2 from both sides
x = 12 - 2
x = 10

For the first question the answer is a, for the second c, for the third d, for the 4th b, for the 5th a