Hi!!
To solve this, do these steps..
(S1): Do the parenthesis..
5.4 = a - (-1.8) ===> 5.4 = a + 1.8
(S2): Subtract 1.8 from both sides, isolate the '1.8'.
5.4 = a + 1.8 ===> 5.4 - 1.8 = a
(S3): Do the subtraction..
5.4 - 1.8 = a ===> a = 3.6
Hope l helped!
