Answer:
∠BDC=43°
Step-by-step explanation:
Since ABCD is a rectangle, ∠ADC=90
∠ADC=∠BDC+∠ADB
90=(7x+1)+(9x-7)
90=16x-6
16x=96
x=6
∠BDC=7x+1
=7(6)+1
=42+1=43
