1/2(y-40)=-13.5 what is the answer i need help

1
2
(

−
4
0
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=
−
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3
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5

1
2
(

−
4
0
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=
−
1
3
.
5
1
2
(
y
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40
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=
−
13.5
21(y−40)=−13.5
1
(

−
4
0
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2
=
−
1
3
.
5
That’s the answer

“exterior angles of triangles. an exterior (or external) angle is the angle between one side of a triangle and the extension of an adjacent side. try this drag the orange dots on any vertex to reshape the triangle.” look to get to the answer i explained what it means and other things i hope it you .