SOLUTION: Let <A and <B be supplementary angles and let m<A = (x + 12)° and m<B = (3x + 20)°. What is the value of x? What are the measures of the angles?

Algebra ->  Angles -> SOLUTION: Let <A and <B be supplementary angles and let m<A = (x + 12)° and m<B = (3x + 20)°. What is the value of x? What are the measures of the angles?      Log On


   

Question 647477: Let
Answer by MathLover1(20849) About Me  (Show Source):
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given:
Let < A and < B be supplementary angles, and
let m < A+=+%28x+%2B+12%29° and m < B+=+%283x+%2B+20%29°.
What is the value of x?
What are the measures of the angles?
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Supplementary Angles add up to 180°.
So, A%2BB=180............1
m < A+=+%28x+%2B+12%29 and m < B+=+%283x+%2B+20%29°...plug it in 1

x+%2B+12%2B3x+%2B+20=180............1
4x+%2B+32=180
4x=180-32
4x=148
x=148%2F4
x=37........the value of x
the measures of the angles:
m < A+=+%28x+%2B+12%29
m < A+=+%2837%2B+12%29
m < A+=+49°
m < B+=+%283x+%2B+20%29°
m < B+=+%283%2A37+%2B+20%29°
m < B+=+%28111+%2B+20%29°
m < B+=+131°