Starting from (−1)×5, write various products showing some pattern to show (−1)×(−1)=1.
−1×5=−5
−1×4=−4=−5+1
−1×3=−3=−4+1
−1×2=−2=−3+1
−1×1=−1=−2+1
−1×0=0=−1+1
Therefore,−1×(−1)=0+1=1
Question 4 Starting from (−1) × 5 ,write various products showing a pattern to show (−1) × (−1)=1.