Answer:
[tex] m\angle SXW =113\degree [/tex]
Step-by-step explanation:
In circle with center X, VS is diameter.
So [tex] \widehat {SWV} [/tex] is a semicircular arc.
[tex] \therefore m\widehat{SWV} = 180\degree [/tex]
[tex] \therefore (12x+7)\degree + (21x +8)\degree = 180\degree [/tex]
[tex] \therefore (33x+15)\degree = 180\degree [/tex]
[tex] \therefore 33x+15 = 180 [/tex]
[tex] \therefore 33x = 180-15 [/tex]
[tex] \therefore 33x = 165 [/tex]
[tex] \therefore x =\frac{165}{33} [/tex]
[tex] \therefore x =5 [/tex]
[tex] m\angle SXW =m\widehat{SW} [/tex]
(Measure of central angle is equal to the measure of its corresponding minor arc)
[tex] m\angle SXW =(21x + 8)\degree [/tex]
[tex] m\angle SXW =(21\times 5+ 8)\degree [/tex]
[tex] m\angle SXW =(105+ 8)\degree [/tex]
[tex] m\angle SXW =113\degree [/tex]
