![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
The expression is ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=9fe8118120fa711ba99dc768ddc0443c.png\")
.
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=e1141e8edad02c35357fb99ea5fe4d9e.png\")
(Substitute x = 7.1, y = - 2.5)
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=16be46db3b6010ca377dff8d941db251.png\")
(Product of two same signs is positive)
To subtract 2.5 means add - 2.5.
\![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=924dd029b9af4619de184d217ef7a6a9.png\")
= 4.6 (Add: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=2dbedcf524e30442e39914ab16702aa9.png\")
)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
The value of the expression is 4.6.