Erik draws quadrilateral ABCD . If side AB=40x , side BC=4+3y , side CD=8x+32 , and side AD=9y−20 , for what values of x and y can Erik be sure that his quadrilateral is a parallelogram?(1 point) Responses x=40 and y=16 x equals 40 and y equals 16 x=4 and y=1 x equals 4 and y equals 1 x=20 and y=8 x equals 20 and y equals 8 x=1 and y=4

1 answer

For quadrilateral ABCD to be a parallelogram, opposite sides must be equal. Thus, we need to set the sides equal in pairs:

  1. \( AB = CD \)
  2. \( BC = AD \)

Substituting the side lengths we have:

  1. \( 40x = 8x + 32 \)
  2. \( 4 + 3y = 9y - 20 \)

Now let's solve each equation.

1st Equation:

\[ 40x = 8x + 32 \]

Subtract \( 8x \) from both sides:

\[ 40x - 8x = 32 \] \[ 32x = 32 \]

Dividing both sides by 32:

\[ x = 1 \]

2nd Equation:

\[ 4 + 3y = 9y - 20 \]

Rearranging gives:

\[ 4 + 20 = 9y - 3y \] \[ 24 = 6y \]

Dividing both sides by 6:

\[ y = 4 \]

So we have found that \( x = 1 \) and \( y = 4 \).

Now, we check the given options to confirm:

  • \( \text{x = 1 and y = 4} \) is an option.

Thus, the correct values for \( x \) and \( y \) that ensure the quadrilateral is a parallelogram are:

x = 1 and y = 4.