![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
The equation is – 5 + a = 21.
\(Apply addition property of equality: If a = b, then ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=3f126be3dbd24861d4e069dac63c3f83.png\")
)
– 5 + a + 5 = 21 + 5 (Add 5 to each side)
\– 5 + a + 5 = 21 + 5 (Apply additive inverse property: – 5 + 5 = 0)
\a = 26 (Add: 21 + 5 = 26)![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
Check:
\To check the solution substitute a = 26 in original equation.
\– 5 + 26 = 21
\21 = 21 (Add: – 5 + 26 = 21)
\The equality is true.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The value of a = 26.