Answer: 1 3/10a+19 Step-by-step explanation:Ok so first you have to open the parenthesis. Since the sign to the left of both the parenthesis is positive we can just normally open the parenthesis . We get: 1/2a+12+4/5a+7We need to convert the denominators of 1/2a and 4/5a so we can add them together1/2a=5/10a4/5a=8/10aNow we can add the a variables together.5/10a+12+8/10a+7=13/10a+12+7Then add 12 and 7 together:13/10a+19 = 1 3/10a+19Keep in mind: If the sign to the left of the leftmost parenthesis is negative then the sign inside the parenthesis is negative.For example when opening this parenthesis: (2+3/x)-(2+3x) the sign is negative so the opening parenthesis is -2-3x.