2m+3=23
2m=20
m=10
let me know in the comments if you need further explanation :)
Answer:
68°
Step-by-step explanation:
As BA⊥BD, so ∠ABD = 90°
also, ∠ABD = ∠CBD + ∠ABC
⇒ 90° = 4x + 52° + 8x - 10°
⇒ 12x = 48°
⇒ x = 4°
now,
∠CBD = 4x + 52°
= 4(4°) + 52°
= 68°
Answer: The answer is C
Step-by-step explanation: