If ADAB
ACBA,
ZDAB = 35° and ZCBA = 8x + 3
A
D
x = [?]
X
C
B

Answer:
x=4
Step-by-step explanation:
We are given that the triangles are congruent.
Specifically, the order of the letters gives that the angles ∠DAB and ∠CBA are corresponding parts of the two congruent triangles. Since corresponding parts of congruent triangles are themselves congruent, ∠DAB ≅ ∠CBA. Thus, m∠DAB = m∠CBA.
Given the expressions for the two angles, we can substitute into the equation, and solve for the requested variable.
[tex]m\angle DAB=m\angle CBA\\(35)=(8x+3)\\(35)-3=(8x+3\!\!\!\!\!\!\!\!\!\!{--})-3 \!\!\!\!\!\!\!\!\!\! {--}\\32=8x\\\dfrac {32}{8}=\dfrac {8x\!\!\!\!\!\!\! {-}}{8\!\!\!\! {-}}\\4=x[/tex]