Please help with this one, geometry

9514 1404 393

  a) 40°

  b) 70°

  c) 35°

  d) 105°

Step-by-step explanation:

a) x is half the given angle, so is ∠BAC/2 = 80°/2.

  x = 40°

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b) ∠ABC has a value that makes the angles in the triangle have a sum of 180°.

  ∠ABC +∠BAC +30° = 180°

  ∠ABC = 180° -30° -80°

  ∠ABC = 70°

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c) y is half the measure of ∠ABC, so is 70°/2.

  y = 35°

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d) z has a value that makes the angles in its triangle have a sum of 180°.

  x + y + z = 180

  z = 180 -x -y = 180 -40 -35

  z = 105°

45

step-by-step explanation:

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,