The equation is .
Subtract 6 from each side.
Apply commutative property of addition: .
.
The option D is correct answer.
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=bbe33b4ee489992345c6c67c07cb52e9.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=9c2d2c1da2d5d31d3fef55208fc761be.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=94da50b59bf0b0ae6ad23e247f52add8.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a371477fefa231e98b7c5783e15d8534.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=672215c26d1d6a372e655978e38f38f8.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=bec6cd01cabbf2399209aed51af90bd4.png\")
.![\"\"](\"/userfiles/image/steps_images/solution.JPG\")