Answer:
x=3.52 and m<BCD= 29.63 degrees
Step-by-step explanation:
I might be wrong but i think its worth a shot
All angles in a right angled triangle equals 180
and we know that the triangle is right angled because the line segment BD is tangent to the circle A at point B which makes the line BC perpendicular to line BD so we have two expression for our angles and other one is 90 so sum the sum of all three angles should be 180
[tex](7x+5)+(20x-10)+90=180[/tex]
[tex]27x=95[/tex]
[tex]x=3.52[/tex]
and hence the value of x is 3.52 and the angle m<BCD is
m<BCD= [tex]7x+5[/tex]
m<BCD= [tex]7(3.52)+5[/tex]
m<BCD= [tex]29.63[/tex]
