Answer: [tex]17^{\circ}[/tex]
Step-by-step explanation:
Given
[tex]\angle A=(x+8)^{\circ}[/tex]
[tex]\angle B=(8x+1)^{\circ}[/tex]
Angle A and B are complementary i.e. sum of the two must be [tex]90^{\circ}[/tex]
[tex]\Rightarrow \angle A+\angle B=90^{\circ}\\\Rightarrow x+8+8x+1=90^{\circ}\\\Rightarrow 9x=90-9=81^{\circ}\\\Rightarrow x=9^{\circ}[/tex]
[tex]\therefore \angle A=x+8^{\circ}=9+8\\\Rightarrow \angle A=17^{\circ}[/tex]