half a number plus 5 is 13 . what is the number ?
"let x be the number . always replace ` ` is ' ' with an equal sign ( 1 / 2 ) x + 5 = 13 ( 1 / 2 ) x = 13 - 5 ( 1 / 2 ) x = 8 x = 16 correct answer is b"
multiply(subtract(13, 5), const_2)