Coba Kerjakan! [+] × [+] = [+] [−] × [−] = [+] [−] × [+] = [−] [+] × [−] = [−] + + − − + 2 + 7 2 + 9 2 + 9 −5 5 + 1 3 + 8 4 + 9 4 + 9 −2 − 7 2 + 7 2 2 2 2 3 − 2 2 − 4 − − + 2 − − 2 2 2 2 − 1 1 − 3 4 + 1 − − 1 + 1 5 2 − 4 2 + 1 −2 + 9