Question

Va roggg...urgent ... cele incercuite! Va rogg

Answer 1

2)  (x+2)²-(x+1)(x-1)=x²+2x+4-(x²-x+x-1)=x²+2x+4-(x²-1)=x²+2x+4-x²+1=2x+4+1=2x+5
3) (√2-1)²-(1-√2)²=√2²-2 √2+1²-(1²-2 √2+√2²)=2-2√2+1-(1-2√2+2)=3-2√2-(3-2√2)=3-2√2-3+2√2=0
6)  a+b=4 a-b=2; a²-b²=?
(a+b)×(a-b)=a²-b²=4²-2²=16-4=12
8)  (x-1)(x+1)((x²+1)=(x²-1)(x²+1)=x⁴+x²-x²-1=x⁴-1
9)  (x-2)(x+2)(x²+4)(x⁴+16)=(x²-2²)(x²+4)(x⁴+16)=(x²-4)(x²+4)(x⁴+16)=(x⁴-4²)(x⁴+16)=(x⁴-16)(x⁴+16)=(x⁴)²-16²=x⁸-256