If a b = a + ba - b, then (6 4) 3 =

jmc

prealgebra junior

Problem

a \otimes b = \frac{a + b}{a - b}

, then

(6 \otimes 4) \otimes 3 =

(A)

4

(B)

13

(C)

15

(D)

30

Solution

6 \otimes 4 = \frac{6 + 4}{6 - 4} = 5

5 \otimes 3 = \frac{5 + 3}{5 - 3} = 4, 4

Final answer