3/7 * -2 1/5 = (turn ur mixed number into an improper fraction)
3/7 * - 11/5 = (now just multiply straight across)
(3 * -11) / (7 * 5) = -33/35 <====
a) (0.17 ac)×(126 min/ac) = 21.42 min
b) I can mow 1/126 ac/min; you can mow 1/117 ac/min. Together, we can mow at a rate that is the sum of these:
... (1/126 + 1/117) ac/min = (117 + 126)/(126×117) = 243/14,742 ac/min
Then it will take 14,742/243 min/ac × 0.17 ac/lawn ≈ 10.31 min/lawn
C. The distance around the circle is the correct answer.