It 246/1000 hope this helps :D
Step 1 : Simplify both sides
-5(6a+21)=-15
(-5)(6a)+(-5)(21)=-15
-30a-105=-15
Step 2 : Add 105 to both sides
-30a-105+105=-15+105
-30a=90
Step 3 : Divide both sides by -30
-30a=90
—————
-30 -30
a = -3
<h3>
Answer: 161 degrees</h3>
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Explanation:
Line AE is a tangent while line AU is a secant. The angle formed by the secant and tangent lines connects with the arcs through this formula
secant tangent angle = (larger arc - smaller arc)/2
More specifically, we can say:
angle EAI = (arc EU - arc IE)/2
42 = ( (7m+5) - (3m-1) )/2
42*2 = (7m+5) - (3m-1)
84 = 7m+5 - 3m+1
84 = 4m+6
4m+6 = 84
4m = 84-6
4m = 78
m = 78/4
m = 39/2
m = 19.5
Use this value of m to compute each arc
- arc IE = 3m-1 = 3*19.5-1 = 57.5 degrees
- arc EU = 7m+5 = 7*19.5+5 = 141.5 degrees
Let's say arc IU is some unknown number x. It must add to the other two arc measures to form 360 degrees, which is a full circle.
(arc IU) + (arc IE) + (arc EU) = 360
x + 57.5 + 141.5 = 360
x + 199 = 360
x = 360-199
x = 161
The measure of minor arc IU is 161 degrees
