(1) Please verify the correctness of this equation;
When a= 1, b=0 and c=- 1.
Left = 1? +0? +(- 1)? - 1×0-[0×(- 1)]-[ 1×(- 1)]=3
Right =? [﹙ 1-0﹚? +﹙0-(- 1)﹚? +﹙(- 1)- 1﹚? ]=3
(2) If A = 2009, B = 20 10 and C = 20 1 1, can you find A quickly? +b? +c? -the value of ab-ba-AC?
Answer? +b? +c? -ab-ba-ac
=? [﹙2009-20 10﹚? +﹙20 10-20 1 1﹚? +﹙20 1 1-2009﹚? ]=3
2. Solve the equation: (x+3)(x-2)-(x+ 1)? =﹣ 1
(x+3)(x-2)=(x+ 1)? ﹣ 1
(x+3)(x-2)=(x+ 1﹣ 1)(x+ 1+ 1)
(x+3)(x-2)=x(x+2)
x? +x-6=x? +2 times
x=-6