eric draws quadrilateral ABCD. if side AB=40x, side BC=3y+4, side CD=8x+32and sideb AD=7y-8, for what values of x and y can erick be sure that his quadrilateral is a parallelogram?

1 answer

For a quadrilateral to be a parallelogram, opposite sides must be equal. In quadrilateral ABCD, we have the following sides:

  • Side AB = \( 40x \)
  • Side BC = \( 3y + 4 \)
  • Side CD = \( 8x + 32 \)
  • Side AD = \( 7y - 8 \)

According to the properties of a parallelogram, we can set the following equations based on opposite sides being equal:

  1. \( AB = CD \) \[ 40x = 8x + 32 \]
  2. \( BC = AD \) \[ 3y + 4 = 7y - 8 \]

Let's solve each equation.

Solving for \( x \):

Starting with the first equation: \[ 40x = 8x + 32 \] Subtract \( 8x \) from both sides: \[ 32x = 32 \] Now divide both sides by 32: \[ x = 1 \]

Solving for \( y \):

Now let's solve the second equation: \[ 3y + 4 = 7y - 8 \] Subtract \( 3y \) from both sides: \[ 4 = 4y - 8 \] Add 8 to both sides: \[ 12 = 4y \] Now divide both sides by 4: \[ y = 3 \]

Conclusion:

The values of \( x \) and \( y \) that will make quadrilateral ABCD a parallelogram are: \[ x = 1 \quad \text{and} \quad y = 3. \]