Question

Two opposite angles of a parallelogram are (5x-2)°and (40-x)°.find the value of x.

Answer 1

The opposite angles of a parallelogram are equal so,

5x-2=40-x
6x=42
x=7

Hope it helps!!!

Answer 2

opposite angles of a parallelogram are equal , therefore
$5x - 2 = 40 - x \\ 6x = 42 \\ x = 42 \div 6 \\ x = 7$