Answer:
IU = 161
Explanation:
Angle Formed by Two Secants= 1/2 (difference of Intercepted Arcs)
42 = 1/2 (7m+5 - (3m-1))
Distribute the minus sign
42 = 1/2 (7m+5 - 3m+1))
Combine like terms
42 = 1/2 ( 4m+6)
Distribute the 1/2
42 = 2m+3
Subtract 3 from each side
42-3 = 2m+3-3
39 = 2m
Divide by 2
19.5 = m
The sum of the arcs = 360
IU+ 3m-1 + 7m+5 = 360
IU +10m+4 = 360
IU +10(19.5) +4 = 360
IU +195+4 = 360
IU = 360 - 199
IU=161