Question

For what value of x must ABCD be a parallelogram?

Answer 1

x = 3

Explanation:

to be a parallelogram opposite sides have to be equal

so we have

`DC = AB\\\\20x-7 = 16x+5`

now solve for x

`20x-7+7 = 16x+5+7\\\\20x = 16x + 12\\\\20-16x = 16x+12-16x\\\\4x = 12\\\\x = (12)/(4) = 3`