From the question, we know that the sum of BC and CD equals BD.
BD = BC + CD = 7x - 10
BC = 4x - 29
CD = 5x - 9
Let's set BC and CD equal to BD
4x - 29 + 5x - 9 = 7x - 10
Combine like terms on the left side.
9x - 38 = 7x - 10
Add 38 to both sides and subtract 7x from both sides.
2x = 28
Divide both sides by 2
x = 14
