For what values of the variables must ABCD be a​ parallelogram?

5 y degrees5y°
5 x degrees5x°
left parenthesis y plus 76 right parenthesis degrees(y+76)°
left parenthesis 6 x minus 17 right parenthesis degrees(6x−17)°

1 answer

To determine the values of the variables such that ABCD is a parallelogram, we need to use the properties of a parallelogram. Specifically, we rely on the properties of opposite angles in a parallelogram, which states that opposite angles are equal.

Given angles:

  • \( \angle A = 5y^\circ \)
  • \( \angle B = 5x^\circ \)
  • \( \angle C = (y + 76)^\circ \)
  • \( \angle D = (6x - 17)^\circ \)

Since angles A and C are opposite angles, we can set them equal to each other:

\[ 5y = y + 76 \]

Now, subtract \( y \) from both sides:

\[ 5y - y = 76 \ 4y = 76 \ y = \frac{76}{4} = 19 \]

Next, we use the property that angles B and D are opposite angles, so we can set them equal to each other:

\[ 5x = 6x - 17 \]

Subtract \( 5x \) from both sides:

\[ 0 = x - 17 \ x = 17 \]

Consequently, the values of the variables that would make ABCD a parallelogram are:

  • \( y = 19 \)
  • \( x = 17 \)

To summarize:

  • \( y = 19 \)
  • \( x = 17 \)