Find the value of x and each arc measure.

12 and 13 please

See answers below;

Step-by-step explanation:

Find the diagram attached

12) Given the following

m<EF = 3x - 6

m<GF = 15x - 30

From the diagram, arcEf and arcGF are supplementary. Hence;

arcEF + arcGF = 180

3x - 6 + 15x - 30  = 180

18x - 36 = 180

18x = 180 + 36

18x = 216

x = 216/18

x = 12degrees

arcEF = 3x-6

arcEF = 3(12) - 6

arcEF = 36 - 6

arcEF = 30degrees

arcGF = 180 - aecEF

arcGF = 180 - 30

arcGF = 150degrees

Since arcDE = arcGF (vertical angles), hence arcDE = 150degrees

arcDFG = arcDG+arcGF

arcDFG = 30 + 150

arcDFG = 180degrees

13) arcMN = arcQP (vertical angles)

12x-5 = 6x+3

Collect like terms

12x - 6x = 3 + 5

6x = 8

x = 8/6

x = 1.3

arcMN =12x - 5

arcMN = 12(8/6) - 5

arcMN = 16 - 5

arcMN = 11degres

arcNP = 180 - arcMN

arcNP = 180 - 11

arcNP = 169degrees

Since arcNQP lies on straight line, hence arcNQP is 180degrees