Respuesta :

s1m1
The inscribed angle is 8 x+10 and it has to be half of the arc 12x+40 we ca write as
2(8x+10)=12x+40
16x+20=12x+40
16x-12x=40-20
4x=20
X=5
The angle at the centre of a circle is twice that at the circumference. The length of arc is 12x+40=2(8x+10).
12x+40=16x+20, 20=4x so x=5.