![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
The equation is 18 + z = 40. \ \
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Subtraction property of equality: If a = b, then a ![\"\"](\"/MathKey/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c7a8c800d2df7d176b09fff75181eb8f.png\")
c = b ![\"\"](\"http://c4anything.com/MathKey/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c7a8c800d2df7d176b09fff75181eb8f.png\")
c.
18 + z 18 = 40 18 (Subtract 18 from each sides)
z = 40 18 (Additive inverse property:18 18 = 0
z = 22 (Subtract: 40 18 = 22)
![\"\"](\"/userfiles/image/steps_images/step2.JPG\")
Check:
\To check the solution, substitute z = 22 in original equation.
\ 18 + z = 40![\"\"](\"/MathKey/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=cf88eb4b75e2e087ff1d68b5148e102c.png\")
18 + 22 = 40
40 = 40 (Add: 18 + 22 = 40 )
\Compare the values, the equation is true. The solution is z = 22.
\![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
The value of z = 22.
\