Question

13 = 5 - 13 +3a (&how did you get the answer ?)

Answer 1

26-5=3a
21/3=a
a=7

Answer 2

simplify
13=-8+3a
add 8 to both sides
21=3a
divide by 3
a=7

Answer 3

13 = -8 +3a
3a = 21
a = 7

Answer 4

13= 5-13 +3a So,according to the order of operations (PEMDAS), you first figure out the multiplication, but forgetting about it I'll go to 13 - 5, which is 8. 21(3a)-8+13 and that is how you get your answer!!! Therefore, a=7.