25-(y+3)=10
my notebook says the answer is 12 ... but
28-y = 10
-y = 10-28
-y . = -18
???
25 - (y+3 )= 10 apply the negative over the terms in the parentheses
25 - y - 3 = 10 combine like terms on the left side
22 - y = 10 add y to both sides, subtract 10 from both sides
12 = y
